In order to further exploit the high-yield potential of peanuts and promote large-scale unit yield through demonstration, the Team of Peanut Cultivation and Physiological and Ecological Innovation Team from Shandong Academy of Agricultural Sciences has been consistently organizing high-yield research since 2013. Yields successively broken through the actual unit yield of 11 250 kg/hm2, 11 700 kg/hm2, and 12 000 kg/hm2, with the highest yield reaching 12 982 kg/hm2 in 2023. This paper conducts an analysis of the factors contributing to the high-yield records, including cultivation techniques, climate conditions, and yield components, and compares the input and output. In terms of cultivation technology, the high-yield cultivation technology system integrates single seeds precision sowing, whole process-controlled fertilization, coupling with bio-fungicides, and three-preventions and three-promotions regulatory approach. By fully utilizing the production potential of individual plants and cultivating high-quality populations to achieve high yields, which provides technical support for the next breakthrough in achieving a unit yield of 13 500 kg/hm2.
To improve peanut yield, density effect of single-seed sowing was explored on flowering dynamics and fruiting characteristics. A common large peanut variety Huayu 25 was used as material, 4 treatments of single-seed sowing of 278 000 plants·hm-2 (S9, plant spacing 9 cm), 208 000 plants·hm-2 (S12, plant spacing 12 cm), 167 000 plants·hm-2 (S15, plant spacing 15 cm) and double-seed sowing of 278 000 plants·hm-2 (D18, plant spacing 18 cm) were set under the same row spacing. Differences were investigated on flowering habits, needle formation, pod development dynamics, pod setting range and yield of peanut. Results showed that different densities of single-seed sowing could all promote peanut early flowering, with more flowerings. They increased the number of effective needles and promoted pod development to different degrees. The effect was most obvious under low density conditions. From the perspective of population indicators, under single-seed precision sowing mode of 208 000 plants·hm-2, peanuts have the highest number of flowerings, effective needles, and pods, the largest pod volume, pod fullness, and the highest yield level. Different densities of single-seed sowing changed pod setting range and pod spatial distribution of peanuts. The pod setting range increased with the decrease of density. However, most of the pods (more than 95%) in each treatment were still distributed within the spatial range of 6.0 cm radius. Under single-seed sowing of 208 000 plants·hm-2 (plant spacing 12.0 cm), the pod setting range was close to half of plant spacing which was more conducive to uniform distribution of pod among populations.
To make full use of natural resources, suitable planting patterns and densities for peanut under different soil fertility levels were investigated, using HY60 as material. Total of 12 planting densities were set under 2 planting patterns of single-seed sowing (SS) and double-seed sowing (DS). Their effects on agronomic traits and yield of peanut were studied by random block design. Results indicated that under high soil fertility level at Banquan site, appropriately reducing density was beneficial for achieving high yield. When planting pattern was SS12 at the density between 200 000 to 220 000 holes/hm2 (the pattern includes SS12-75 and SS12-80, e.g. single-seed sowing, hole distance 12 cm, ridge width 75 and 80 cm), the plants grew vigorously with high dry matter accumulation and high allocation and transfer rate to pods, with the distribution rate ranged from 58.67% to 59.07%. Therefore, ultimately higher yield could be obtained from higher pods number, higher saturation rate, higher biomass accumulation, and higher economic coefficient. The pod yields of SS12-75 and SS12-80 were 17.36% and 18.98%, both higher than the lowest yield treatment DS16-75 (e.g. double-seed sowing, hole distance 16 cm, ridge width 75 cm), and 5.49% and 6.94% higher than the average yield of all treatments, respectively. At low soil fertility level on Laopo site, due to insufficient soil nutrients, plants were stunted, with fewer fruits, lower full pod rate, and lower production potential per plant. The highest yield was obtained by DS18-70. Patter SS10-70 which using 11.1% less sowing seeds, had a 2.48% lower yield than DS18-70, with only 1.99% less net pod yield. It indicated that both DS18-70 and S10-70 patterns could be selected for production. In order to make full use of natural resources and alleviate inter plant competition, it was suggested to plant by reducing ridge spacing and expanding hole distance.
To address the issue of low seeding rate and unstable sowing quality on the peanut film during precision seeding, a planting monitoring system of air-suction peanut burrow planter was designed based on infrared optical fiber sensor. STM32F407VGT6 single chip microcomputer and encoder were used to collect speed pulse signals and seeding time interval information. Real-time monitoring of seeding quality information such as single seed seeding rate, missing seeding rate and reseeding rate was realized. Results showed that when the sensor installation distance was 3.1 mm with installation angle of 3.2°, the monitoring accuracy of seeding was the best, which had a single seed monitoring accuracy of 95.98%, missed seeds monitoring accuracy of 95.91%, and a single seed replay monitoring accuracy of 93.28%. Bench test results showed that when the operation speed of burrow planter was 3-5 km/h, the monitoring accuracy of single seed could be > 95%, with monitoring accuracy of miss seeding > 91%, monitoring accuracy of replayed > 90%. Field experiments results showed that the accuracy of single seed monitoring could be > 93%, missed sowing monitoring >90%, replay monitoring >88%, when the operating speed was 3-5 km/h. In summary, this air-suction peanut dibbler seeding monitoring system might meet the needs of real-time monitoring of seeding quality in peanut seeding process, provide data reference for actual seeding operations, and ensure higher seeding quality in the whole sowing process.
For peanut yield reduction by continuous cropping, soil layer replacement were designed by deep turning plow. The design and test focused on mechanical design and motion analysis of overturning mechanism of the replacement, and force analysis of plow body surface. To verify the operational performance of soil displacement deep turning plow, three-factor quadratic rotary orthogonal combination field pre-test was carried out with plowshare mounting angle, plowing width and operational speed as the test factors. Coefficient of variation of plowing depth, vegetation stubble coverage and cfa rate as performance evaluation indexes were investigated to obtain the response surface model of each factor. Influence of each factor was studied on performance aiming to the lowest coefficient of variation of plowing depth, the highest vegetation stubble coverage and the highest cfa rate. Factor optimizing results indicated as follows: plow depth coefficient of variation of 3.35%, vegetation residue coverage of 93.95%, and turnover rate of 94.39% at a plowshare mounting angle of 25.58°, a plowing width of 526.01 mm, and an operating speed of 5.82 km/h. These optimum results were based on the optimised performance of the plowshare model. Then by 5 gradients of operation speed set for field verification tests, the validation test showed that when soil layer replacement deep turning plow was operated with the optimal plowshare installation angle and plowing width, the coefficient of variation of plowing depth was less than 4%, the residual stubble coverage rate was greater than 90%, and cfa rate was greater than 90% at each speed gradient, which met the quality requirements of turning plow operation. In 2 consecutive years of application on continuous peanut land, the peanut yield increased by 21.2% in 2022, and 16.9% in 2023.
In order to establish a high-yield model with reasonable planting density under cross planting mode, the effects of planting density on agronomic characteristics, group structure changes and yield were studied with semi-trailing type peanut variety Fuyu Silihong and erect type Jihua 17 as materials. Planting densities were set in 6 modes, M1 (2.385 ×105 plants/hm2), M2 (2.084×105 plants/hm2), M3 (1.852 ×105 plants/hm2), M4 (1.666 ×105plants/hm2), M5 (1.389 ×105 plants/hm2), M6 (1.191 ×105plants/hm2). Double grain seeding (2.385 ×105plants/hm2) was used as control (CK). Plant traits, SPAD, dry matter accumulation and yield traits of individual peanut varieties under different planting density were measured. With the decrease of planting density, the main stem height and side branch length of the two varieties gradually increased. The semi-trailing peanut variety Silihong had the highest main stem height and side branch length under M6 density. The erect peanut variety Jihua 17 increased first and then decreased with planting density, and the main stem height and side branch length were the highest under M5 density. With the decrease of planting density, the SPAD values of the two varieties in pod setting stage and harvest stage tended to decline first and then rise. The accumulation of dry matter of single plants (aboveground and underground) of M4, M5 and M6 during the harvest stage of Silihong were significantly higher than that of CK, that of Jihua 17 at M4 had increased significantly compared with CK, had increased by 155.35% and 23.31% respectively compared with control in harvest. In addition, with the decrease of density, Silihong yield increased first and then decreased, pods per plant, 100-pod weight and pod yield per plant were all on the rise and then declined, and kilogram pods count was lower than that of CK. The yield of Jihua 17 was decreased, number of pods per plant and pod yield per plant showed an upward trend, and kilogram pods count was less than CK. In summary, cross plant + single-seed planting mode could increase peanut height, SPAD and dry matter accumulation, and subsequently increase yield. Under cross planting, the appropriate sowing density should be selected according to peanut type, M4 density for semi-trailing type might be the best, and M2 density for erect type might be the best.
In order to verify the effects of different storage methods on the germination of peanuts, the high oleic acid peanut variety Yuhua 37 and Kainong 1715, the high oil peanut variety Yuanza 9102 and Yuhua 9326 were used as test materials, and different storage temperatures and packaging methods were selected to study the effects of different storage methods on seed germination ability, oxidation degree and endogenous hormone content. The results showed that peanut type, storage temperature and packaging method had significant effects on the storage resistance of peanut seeds. Higher oleic acid content, low temperature and storage conditions in ziplock bags could effectively slow down the oxidation process and maintain the content of endogenous hormones in seeds at a relatively high level, thus ensuring seed vigor and germination ability. Compared with normal temperature storage, low temperature storage could better maintain the vitality of seeds. After 39 months of low temperature storage, the average germination rate of the four varieties was above 82%, while the average germination rate of the four varieties stored at normal temperature was less than 32%. The packaging method of ziplock bags was better than plastic bags and mesh bags. After 39 months of low temperature storage, the germination rates of ziplock bags, plastic bags, and mesh bags were maintained at about 85%, 83%, and 80%, respectively. After 39 months of normal temperature storage, the germination rates of ziplock bags, plastic bags, and mesh bags were maintained at about 38%, 33%, and 24%, respectively. The peanut varieties with high oleic acid were more resistant to storage. After 39 months’ storage, the average germination rate of two high oleic acid varieties could be maintained above 75%, but the average germination rate of two normal peanut varieties was less than 40%. As far as peanut types are concerned, the storage resistance of high oleic acid peanuts is better than that of ordinary peanuts, and reducing the ambient temperature and increasing the sealing degree of the package can also improve the activity of the seeds after storage to a certain extent.
In order to explore the effects of sowing depth and different wheat straw return methods on peanut seedling physiological characteristics, photosynthetic performance and dry matter accumulation, a wheat-peanut annual positioning experiment was set up. The peanut seasons were designed with split-plot experiments. The main area was wheat straw returning methods, including moldboard plow tillage with wheat residue returning (P), rotary tillage with wheat residue returning (R), no tillage with wheat residue mulching (N); split area was peanut varieties, as large peanut Shanhua 108 (B) and small peanut Shanhua 106 (S); split zone was sowing depth, with 3 cm (3), 5 cm (5), 9 cm (9), 15 cm (15) in 2021 and 3 cm (3), 6 cm (6), 9 cm (9) in 2022. Results showed that under the same straw-returning method, both varieties had significantly increased plant root vigour under shallow sowing (depth of 3 and 6 cm), and root vigour of both varieties under different straw-returning methods showed the trend of moldboard plow tillage > rotary tillage > no-tillage, which indicated that moldboard plow tillage and straw return was more favourable to root development in the seedling stage of peanut. Relative chlorophyll content of leaf blades (as well as relative content of sucrose synthase and sucrose phosphate synthase) under plow tillage with full straw incorporation versus rotary tillage with full straw incorporation methods showed a wave from first increase and then decrease with the sowing depth. Both varieties had higher chlorophyll content, sucrose synthase and sucrose phosphate synthase activities, under the conditions of appropriate shallow sowing (3 and 6 cm). Compared with no-tillage (N), plow tillage (P) and rotary tillage (R) improved net photosynthetic rate of leaf blades and dry matter accumulation. Under the different returning ways, higher height and length of main stems of both varieties showed in an order of plow tillage > rotary tillage > no-tillage. In both plow and rotary tillage, the strongest seedling index of the 2 varieties reached the highest under shallow sowing (3 and 6 cm), which was favourable to strong seedlings. Therefore, the plow tillage with full straw treatment was beneficial to improve root vigour, photosynthetic performance and seedling index of peanut, and the appropriate sowing depths were 5-6 cm (for large peanut) and 3 cm (for small peanut).
Based on strip intercropping technology of maize and peanut, this article described an innovatively developments of high-value production technology of fresh peanut/fresh maize intercropping, taking advantage of the short growth period of fresh maize and the early harvest of fresh peanut, enabling two seasons for the planting of fresh peanut/fresh corn in Huanghuai region. It analyzed the technology key points, including planting mode, varieties selection and machinery, sowing moisture, water management, fertilizer management, plant protection (diseases, pests and weeds prevention), vigorous growth regulation, harvest, storage and transportation. It is expected to provide technical support for popularization of this technology in the main grain and oil producing areas of China.
To ptimize the utilization of temperature, light, and heat resources and enhance the overall benefits of agricultural production in saline-alkali land, the effects of different row positions on photosynthate accumulation, light intensity, chlorophyll fluorescence characteristics, yield, and benefit of peanut were investigated through a field experiment under a high-efficiency cropping pattern with an annual rotation of peanut/cotton 6:4 intercropping. The results demonstrated that: (1) Constant amplitude peanut/cotton intercropping in salt-alkali soil significantly enhanced the main stem height, lateral branch length, and non-photochemical quenching coefficient (NPQ) of functional leaves, while substantially reducing bioaccumulation, SPAD value, leaf area index, net photosynthetic rate, transpiration rate, and yield of intercropped peanut. Simultaneously, the intercropping system increased the number of fruiting branches, boll number per plant, boll weight, yield of intercropped cotton as well as its comprehensive economic benefit. (2) The peak radiation distribution within the canopy on both sides of the intercropped peanut row (IP1 and IP3), peanut monoculture and cotton monoculture all occurred at 12:00; However it was delayed until 14:00 in the middle ridge of the intercropped peanut row (IP2). Moreover, the radiation intensity in IP1 and IP3 was significantly lower compared to that observed in peanut monoculture. (3) The row position significantly influenced the photosynthetic efficiency of peanut-cotton intercropping system after flowering-pegging stage. SPAD, LAI, and NPQ values in IP2 were significantly higher than those in IP1 and IP3, while there were no significant differences between IP1 and IP3. Pn, Gs, and Tr were significantly affected by location and ridge position. In Dongying site, no significant difference was found in the row position of intercropped peanut at neither growth stage. But in Gaotang site, intercropping system significantly reduced Pn, Gs, and Tr of intercropped peanut functional leaves compared to monocrops; and these 3 traits in IP2 were significantly higher than those in IP1 and IP3. Compared to cotton monoculture, the intercropping system increased benefit by 11.94% (Dongying) and 27.08% (Gaotang) respectively. However, the yield of intercropped peanut and cotton were both decreased compared to monoculture at the two testing sites. The land equivalent ratio of intercrop-ping systems exceeded 1.02.
According to data from the National Bureau of Statistics, peanut unit yield in Yunnan is only about 50% of the national average, which seriously challenged the production and development of Yunnan peanuts. In order to improve yield and economic benefits, this paper summarizes the main contents of the green and efficient production technology system for characteristic peanuts in Yunnan. This system integrates core technologies including mechanized production adapted to local conditions, seed coating, dense planting, efficient fertilization with specialized slow-release (controlled-release) fertilizers, and green and efficient control of major diseases and pests. The application of this system has achieved remarkable results. In the core demonstration area completed in 2022-2023, which covering 3377 hm2, peanut average yield reached 5.37 t/hm2, 2.73 times of Yunnan average. Average output value reached 120 791 CNY/hm2. In the area, chemical fertilizers use was simultaneously reduced by about 30%, with labor input in one hectare of 55 less than before. The application of this system has achieved the goals of cost-saving, quality improvement, and efficiency enhancement, contributing significant scientific and technological strength to the development of Yunnan peanuts industry.
In order to further explore the mechanism of peanut continuous cropping obstacle alleviated by maize-peanut intercropping, the effects of maize root exudates on the allelopathy of 3 phenolic acid allelochemicals and their mixtures were studied by the method of collecting maize root exudates and adding them to the medium of peanut seeds and pathogenic bacteria treated with phenolic acids. The results showed that two concentrations (0.75 mmol/L, 1.5 mmol/L) of cinnamic acid, phthalic acid, p-hydroxybenzoic acid and their mixtures mainly had allelopathic inhibitory effects on the growth of peanut embryo and two pathogenic bacteria Fusarium oxysporum and Colletotrichum dematium, namely. Maize root exudates promoted the germination of peanut seeds, and mainly inhibited the germination of Fusarium oxysporum and Colletotrichum dematium. After adding maize root exudates, the allelopathic inhibiting effects of 3 phenolic acids and their mixtures on peanut seed germination were alleviated and the allelopathy indices were reduced by 60.10%-88.11% under low concentration treatment. Their allelopathic inhibiting effects on Fusarium oxysporum were strengthened and the allelopathy indicies were increased by 28.00%-46.55% under high concentration treatment. The direction of allelopathic effect of p-hydroxybenzoic and the mixture of 3 acid phenolic acids on Colletotrichum dematium was changed from promoting effect to inhibiting effect. Maize root exudates could reduce the allelopathic inhibiting effect of autotoxic phenolic acids in peanut continuous cropping obstacle on seed germination and enhance their inhibitory effect on pathogenic bacteria in soil, which might provide theoretical basis for maize and peanut intercropping to alleviate peanut continuous cropping obstacle and is conducive to the coordinated improvement of the comprehensive production capacity of grain and oil crops.
To better understand rotation effects of annual wheat-maize || peanut pattern on carbon accumulation, field experiments were conducted to investigate the changes of annual plant carbon accumulation, soil bulk density, soil aggregate, 0-100 cm soil water content and soil organic carbon. Five patterns were set up, namely, wheat-peanut rotation (W-P), wheat-maize rotation (W-M), wheat-maize || peanut (row ratio 3:4, W-M||P1), wheat-maize || peanut (row ratio 3:6, W-M||P2), wheat-maize || peanut (row ratio 6:8, W-M||P3). Results showed that carbon accumulation of peanut and corn in intercropping mode was significantly lower than those in monoculture mode in 2018-2019, but the carbon-land equivalent ratio of intercropping mode was greater than 1, and M||P2 treatment was the largest. Compared with maize (W-M), the carbon accumulation of wheat (W-M||P) and peanut (W-P) in intercropping increased by 487.09 kg/hm2 to 1148.08 kg/hm2. Intercropping decreased the bulk density of 0-10 cm soil layer in winter wheat season, and increased the proportion of small particle aggregates (0.25-2 mm) in deep soil of winter wheat season and micro-aggregates (< 0.25mm) in surface soil of winter wheat season. In the 3 intercropping modes, the water use efficiency of M||P2 was significantly higher than those of M||P1 and M||P3, increasing by 3.22% and 8.29% , respectively. Intercropping increased the organic carbon content of aggregates in 0-60 cm soil layer of winter wheat season, and increased the soil organic carbon content and storage in 0-60 cm soil layer of wheat stubble. The organic carbon storage of W-M||P2 increased by 2.55% and 4.05% compared with W-M and W-P, respectively. In conclusion, the wheat-maize || peanut annual rotation model reduced the bulk density of surface soil, improved the structure of deep soil small aggregates and surface micro-aggregates, increased carbon accumulation and water use efficiency of crop plants, and increased soil organic carbon storage in 0-60 cm soil layer.
To further explore the regulatory effects of fertilizer techniques as “layered fertilization” and “nitrogen reduction and calcium increase” on peanut kernel quality, field experiments were conducted to clarify the intrinsic relationship between techniques and quality. In experiment 1, two experimental sites (Jiyang and Yinmaquan) were selected, with two calcium fertilizer levels (0 and 600 kg·hm-2) and five nitrogen fertilizer levels (0, 75, 150, 225, 300 kg·hm-2). In experiment 2, field trial was carried out in Jiyang site from 2021 to 2022. Two fertilization methods, namely mechanical laying-strip application (L) and manual surface broadcast application (B), with two fertilizers (SF, slow-release compound fertilizer, with a release period of 100 days; CF, common compound fertilizer) were designed, with a control (N0) of zero nitrogen fertilizer. Results showed that: (1) nitrogen application increased crude protein content in kernel by 1.24-3.57 percentage points. The total amino acid content increased by 1.19-3.70 points, and linoleic acid content by 0.93-2.41 points. Contents of some fatty acids and amino acids increased with the increase of nitrogen application. However, the oil content of the kernel was reduced by 1.70-5.34 percentage points. Compared with the treatment with zero calcium, contents of crude protein and total amino acids in seeds decreased by 0.10-1.55 percentage points and 0.02-1.23 percentage points, respectively under 600 kg·hm-2 calcium, with oil content increased by 0.16-2.62 points. Thus the combination application of N and Ca fertilizers could put down the increase of crude protein and the decrease of oil content. The cultivation of reducing nitrogen fertilizer and increasing calcium fertilizer showed their beneficial to regulate and improve kernel quality. (2) Under the same fertilization method, compared with compound fertilizer (CF), specialized compound fertilizer (SF) treatment increased crude protein and oil content in kernels. Compared with manual surface broadcast (B), layered application of compound fertilizer (CFL) or peanut specific compound fertilizer (SFL) reduced the crude protein and total amino acid contents in kernels by 0.34-1.39 points and 0.14-0.34 points, respectively, while the oil content in kernels increased by 0.22-1.16 points. (3) Significant positive correlations were found between yield and crude protein, yield and total amino acid, and yield and linoleic acid content (P< 0.01). Significant negative correlation was found between yield and oil content, yield and oleic acid content. Extremely positive significant correlations were found between yield and crude protein, total amino acids, linoleic acid content, and also between crude protein and total amino acids, linoleic acid content. Extremely negative significant correlations were found between crude protein and oil content. Negative significant correlations were found between yield and oil content, linoleic acid content. To sum up, in production, it is necessary to increase oil production with high crude protein. It is recommended to adopt the green and efficient cultivation technology of reducing nitrogen and increasing calcium. It is also possible to apply the special compound fertilizer for peanut and support the efficient cultivation technology of layered fertilization.
To clarify the impact of different maize || peanut intercropping patterns on peanut production, dry matter accumulation, yield formation, as well as nitrogen and calcium nutrient absorption were investigated. Five planting modes were set, namely maize monoculture (SM), peanut monoculture (SP), maize || peanut row ratios of 3:4 (IMP1), 3:6 (IMP2), and 6:8 (IMP3). Experimental results from 2018 to 2019 showed that both maize and peanut yields under intercropping were lower than under monoculture, but the land equivalent ratios of the 3 intercropping patterns were all greater than 1, with IMP2 being the highest. For the total yield of the intercropping system, IMP1 and IMP2 showed no significant difference but were significantly higher than IMP3. The total yields of IMP1 and IMP2 were increased by 4.69%-4.70% and 5.04%-5.97% compared to IMP3, respectively. After pod setting, the dry matter, nitrogen, and calcium accumulations of intercropped peanut population were significantly lower than those in monoculture. Among the 3 different intercropping patterns, IMP2 had significantly higher dry matter, nitrogen, and calcium accumulation than IMP1 and IMP3. At maturity, dry matter accumulation of peanut population in IMP2 was increased by 40.07%-47.16% and 25.24%-25.72% compared to IMP1 and IMP3, respectively; nitrogen accumulation increased by 33.63%-43.28% and 26.58%-29.34%, respectively; and calcium accumulation increased by 33.48%-49.06% and 34.25%-38.97%, respectively. These accumulations of the middle ridge (MR) peanut population in IMP2 and IMP3 were higher than those of the east ridge (ER) and west ridge (WR), but the differences were not significant. In conclusion, maize-peanut row ratio of 3:6 exhibited significant intercropping advantages.
To optimize nitrogen (N) fertilizer application, impact of N proportion in two soil layers on peanut N accumulation and yield was studied. Separated N applications were set in peanut fruiting layer (soil layer 0-10 cm) and roots centralized layer (soil layer 10-20 cm). Pot experiment was designed using 9 treatments: N0 with no nitrogen (control); N1 (all-soil-layer nitrogen fertilizer mixed); single-layers as N2 (N application depth of 8 cm) and N3 (N application depth of 16 cm); separated layers with N4, N5, N6, N7 and N8 (with N application proportions of 1:1, 1:2, 1:3, 2:1 and 3:1 at the depth of 8 cm and 16 cm respectively). The amount of N fertilizer applied at each term was 120 kg/hm2. Results showed that compared with the mixed (N1), individual pod weight increased in those with layered N application. The best proportion of layered N application could be 1:2 (N5). Compared with N1 (the mixed), the total number of pods, full fruits number, and pods weight in N5 (1:2) increased by 16.02%, 14.17%, and 14.35% respectively. Layered N application benefited growth of root nodules. Compared with the mixed application (N1), nodules fresh weight and nodule numbers in N5 (1:2) increased by 17.65% and 24.89% respectively. Each layered N application increased dry matter accumulation of roots, stems, leaves, and pods during 3 stages as seedling, pod-setting, and maturation of peanuts. The dry matter accumulation per plant at the maturity stage was in the order of layered N application> deep application (N3) > mixed application (N1) > shallow application (N2) > N0. Among the different layered treatments, N5 had the highest dry matter accumulation. Both deep and layered application of N increased N accumulation. Compared with N1 (mixed), plant N accumulation under N5 was increased by 27.08% and N accumulation of pods increased by 21.33%. In conclusion, compared with single-layer N application, or high percentage of shallow N application, layered application of N (1:2) was more benefit to peanut nodules, also to plant growth, plant N accumulation and pod yield.
To clarify the effect of molybdenum application on nitrogen metabolism enzyme activities and nitrogen utilization in peanut, both pot and field experiments were carried out to investigate peanut enzyme activities of nitrogen metabolism, nitrogen accumulation, nitrogen use efficiency and yield in the key periods were investigated. Two molybdenum levels were used including control (0, no molybdenum) and molybdenum application (0.2 mg·kg-1). Results of both pot and field experiments revealed that, compared with control, molybdenum application significantly improved activities of nitrate reductase, nitrite reductase, glutamine synthetase, and glutamate synthetase in root and leaves at pod setting and maturing stage of peanut. The molybdenum application significantly increased nitrogen accumulation in root, shoots and pods, nitrogen uptake and use efficiency and pod yield. The nitrogen uptake efficiency in 2 growth periods of pod and field experiments was increased on average by 47.79% and 21.65%, and nitrogen use efficiency was increased on average by 10.58% and 13.56%, respectively. The peanut pod yield increased by 38.20% and 25.81%, respectively, under the increased molybdenum application compared with control. Consequently, molybdenum fertilizer could significantly improve enzyme activities related to nitrogen metabolism in peanut roots and leaves, and thus significantly improve the nitrogen accumulation, nitrogen uptake and utilization efficiency and yield of peanut. Application molybdenum fertilizer might be an effective measure to improve peanut yield and nitrogen use efficiency.
To improve saline-alkali land and peanut high yield, impact of winter rapeseed green manure on physicochemical properties of peanut soil in saline-alkali areas was explored. Field experiments were conducted over 3 years in the Yellow River Delta saline-alkali land, effects of winter rapeseed green manure were investigated at different stages on soil structures and features, including bulk density, porosity, aggregate size distribution, and water stability, pH, available nutrients, organic matter, and salt content in the peanut root zone during the pod setting stage. 3 treatments were designed, namely fallow land without winter rapeseed planting, green manure during peanut budding, and green manure during flowering stage. Results demonstrated that the rapeseed manure at different stages significantly reduced soil bulk density of 0-20 cm and 20-40 cm layer. The numbers of soil aggregates with particle sizes ＞2 mm, 1-2 mm, and 0.5-1 mm were increased significantly in 0-20 cm layer. Soil micro aggregates with particle sizes ＜ 0.25 mm were decreased significantly, which led to enhanced water stability of soil aggregates. The green manure significantly increased organic matter, alkaline hydrolyzable nitrogen, available phosphorus, and available potassium in the 2 layers, with average increase of 10.47%-15.80% compared to control; significantly reduced soil salinity, with average decrease of 20.76% compared to control. No significant difference in soil pH was found. Overall effects were observed in the 0-20 cm layer. Peanut yields increased by 22.48% and 29.41%, respectively under manure treatments at budding and flowering stages although their differences were not significant. A significantly positively correlation was found between available nutrients and ＞2 mm soil aggregates. Significantly negatively correlations were found between bulk density and ＞2 mm soil aggregates, salt content and ＞2 mm soil aggregates, bulk density and ＜0.25 mm soil aggregates, available nutrients and ＜0.25 mm soil aggregates. Therefore, winter rapeseed green manure might improve soil properties and thus promote peanut yield by enhancing saline-alkali land soil, increasing available nutrients, and reducing soluble salt content.
To better evaluate planting mode, effects of different peanut rotation patterns were explored on particle size distribution and carbon content in soil aggregates. From 2017 to 2021, studies were carried out in Yantai, Shandong Province, by using local typical crop modes as contols, including winter wheat-summer maize (WM) and spring peanut (CP). Other peanut rotation patterns were set up, namely, WP (winter wheat-summer peanut rotation), PWM (spring peanut → winter wheat-summer maize rotation), and WPWM (winter wheat-summer peanut → winter wheat-summer maize rotation). Effects of planting patterns were investigated on soil aggregate composition and soil organic carbon content, dissolved organic carbon content, and microbial biomass carbon in the aggregates. Results showed that compared with CP mode, the percentage content of 1-2 mm aggregates in 0-40 cm soil layer under PWM and WPWM modes was significantly increased by 14.75-21.25 and 12.47-16.17 percentage points, respectively, and WPWM mode was more conducive to increase average weight diameter of soil aggregates. Soil organic carbon content of aggregates in 0-40 cm soil layer under WPWM mode was significantly higher than that under CP mode, except for the particle size of 0.25-0.5 mm. The contribution rate of soil organic carbon in 0-20 cm soil layer of 1-2 mm and < 1 mm in WP and WPWM mode was significantly higher than those in CP. Under WPWM mode, dissolved organic carbon content of > 5 mm, 0.5-1 mm and < 0.25 mm aggregates in 0-20 cm soil layer were significantly increased by 50.75%-81.18%, 100.12%-120.12% and 69.44%-90.07% compared with the 2 controls (CP and WM), respectively. In WPWM mode, microbial biomass carbon content of 0-40 cm soil layer aggregates increased the most than those of the controls (CP and WM). Compared with the controls in 20-40 cm soil layer, the contribution rate of microbial biomass carbon in 1-2 mm aggregates was significantly increased under PWM, WP and WPWM modes. Soil organic carbon was significantly correlated with dissolved organic carbon, microbial biomass carbon, and dissolved organic carbon with microbial biomass carbon in aggregates of 2-5 mm, 1-2 mm, and 0.5-1 mm. In general, WPWM increased mean weight diameter in 0-40 cm soil layer, the content of fine and large aggregates (1-2 mm), and the content and contribution rate of soil organic carbon, dissolved organic carbon and microbial biomass carbon in 1-2 mm aggregates, which would improve soil structure and be more in line with the needs of green and low-carbon development.
To enhance the yields of cotton and peanut, bacterial community structure and function in root soil under cotton-peanut rotation were studied. Five treatments were investigated, as continuous cotton cultivation, continuous peanut cultivation, cotton-peanut rotation, peanut-cotton rotation, and fallow land. High-throughput gene sequencing of 16S rRNA was used to analyze bacterial community structure and function. Results revealed that crop rotation increased the diversity of root-associated bacterial communities. A total of 5 009 952 valid sequences were obtained from soil samples, with the highest number of OTUs (operational taxonomic units) under fallow land treatment. In rotational cropping systems, Proteobacteria, Acidobacteria, and Actinobacteria were identified as dominant phyla. Additionally, richness of Firmicutes, Bacteroidetes, and Gemmatimonadetes were increased under rotational patterns. Based on different functions, the microbial groups were categorized into 8 classes. Under rotations modes, higher prevalence of functional groups related to microbial genetic inheritance was found. Metabolic-related groups were predominant overall, and significant enrichment of functional protein sets were found associated with human and plant pathogens. These results indicated that cotton-peanut rotation could increase microbial richness and diversity, alter soil microbial community structures, promote nutrient absorption by crop roots, and ultimately enhance crop yields.
Traditional basal application causes insufficient nutrition supply of leguminous crops in sandy loam soil, which leads to cause nitrogen deficiency and premature senescence in late growth stage. To improve peanut yield, effect of nitrogen topdressing at late growth stage on leaf senescence and yield was studied by field experiments using varieties of HY22 (large kernel) and HY39 (small kernel) from 2020 to 2023. Nitrogen fertilizer was applied at the beginning of nodule senescence (90 d after sowing). 5 nitrogen levels of N0, N20 (20 kg/hm2), N40 (40 kg/hm2), N60 (60 kg/hm2) and N80 (80 kg/hm2) were set. Results showed that topdressing “supporting nitrogen” could significantly increase yield. Among the treatments, N40, N60 and N80 led to significantly higher yields in both varieties. Compared with N0, during the 3-year experiment, pod yield of HY22 increased by 8.43%-12.81% (N40), 7.65%-10.82% (N60), and 6.85%-9.52% (N80) respectively, while HY39 increased by 5.28%-17.28%, 5.18%-17.21%, 3.37%-14.19%, respectively. Compared with no fertilization, SPAD and net photosynthetic rate of the 2 varieties under N40 were significantly increased by 10.91%-12.3% and 44.88%-83.58% respectively. Activities of superoxide dismutase, peroxidase and catalase in leaves at late growth stage were also increased by 36.75% and 40.06%, 4.87% and 8.86%, 19.03% and 58.33%, respectively. Accumulation of malondialdehyde in leaves was reduced, accumulation of dry matter in pods was significantly increased, weight of 100 pods was increased, and thus the yield was increased. In summary, under the condition of basal application of 60 kg/hm2 nitrogen fertilizer, with 120 kg/hm2 phosphorus fertilizer (P2O5) and 120 kg/hm2 potassium fertilizer (K2O), the topdressing of 40 kg/hm2 nitrogen fertilizer could significantly increase leaf antioxidant enzyme activity, delay leaf senescence, improve leaf photosynthetic capacity, and thus increase the yield.
Unreasonable application of nitrogen fertilizer led to inhibition of biological nitrogen fixation ability. Interaction effect of nitrogen fertilizer and rhizobium agent was studied for high-efficiency production-increasing of peanut. Two peanut varieties, Nonghua 5 (NH5, low nodulation) and Honghua 16 (HH16, high nodulation) were used as materials. Based on outdoor pot experiments, effects of different nitrogen application rates (N0, N45, N75, N105, N135, N165) were determined, also as seed dressing with distilled water (W), and seed dressing with rhizobium agent (R) on the morphological indexes, nodulation characteristics, photosynthetic characteristics, nitrogen accumulation, enzyme activities related to nitrogen metabolism and yield of peanuts at podding stage (80 days after emergence), in order to investigate the interactive effect of nitrogen fertilizer and rhizobium agents on peanuts. Results indicated that the main stem length, branch length, net photosynthetic rate, chlorophyll content, photosynthetic related enzyme activity, nitrogen metabolism related enzyme activity and yield of peanut exhibited a trend of increasing initially, and followed by decreasing with the increase of nitrogen application rate. Nitrogen application inhibited peanut nodulation to a certain degree. Seed dressing with rhizobium agent could significantly alleviate this inhibitory effect. The number of root nodules of NH5 and HH16 increased by 28.4%-130.5% and 40.5%-178.3%, respectively, compared with distilled water seed treatment. Under the condition of seed dressing with distilled water (W), the photosynthetic enzyme activities and nitrogen metabolizing enzyme activities in peanut leaves reached their maximum value at the nitrogen application rate of N135. Under the condition of seed dressing with rhizobium agent (R), the activities of photosynthetic enzyme and nitrogen metabolizing enzyme in leaves reached their maximum at N105. Compared with W, the yields of NH5 and HH16 were increased by 1.2%-8.3% and 7.5%-11.0% at each nitrogen application rate, respectively. The yields of NH5 and HH16 per plant reached the maximum under N105-R treatment. In conclusion, the combination of nitrogen fertilizer and seed dressing with rhizobium agent could significantly improve peanut nodulation and reduce the dependence on nitrogen fertilizer. Therefore, suitable nitrogen fertilizer combined with rhizobium agent could improve nitrogen fixation ability while maintaining a high yield, which might be a green and effective way to increase peanut output.
In order to investigate the effects of calcium application on dry matter and calcium nutritional of peanut in different soils, pot experiments were carried out in calcium-deficient acidified red soil and calcium sufficient brown soil respectively. The effects of calcium application (CaO 600 kg · hm-2) on the agronomic characteristics, dry matter and calcium absorption, distribution and utilization of peanut in different soils were studied with no calcium application as control. The results showed that calcium application in the red soil could increase the number of branches and the number of main stems green leaves, but the effect was not significant in the brown soil. Calcium application significantly promoted the accumulation of dry matter in different organs of peanuts in different growth stages on the two soils, effectively improved the distribution of dry matter and promoted the "flow" of dry matter from the "source" of nutrients to the "fruit bank". Compared with the treatment without calcium application, the dry matter accumulation in mature pods of brown soil and red soil increased by 51.3% and 60.1% respectively in 2019, and in 2020 it increased by 44.3% and 46.7% respectively. The application of calcium fertilizer promoted the absorption and accumulation of calcium in peanut, increased the calcium content and accumulation amount in different organs of peanut during the whole growth period significantly. At the same time, calcium application increased the distribution rate of calcium in peanut pods and stems, while the distribution rate of calcium in leaves, roots and gynophore decreased to varying degrees. In addition, calcium application effected the quality of peanuts. The O/L value and crude protein content of peanuts in red soil increased by 10.8% and 5.5% respectively, and in brown soil increased by 4.5% and 3.8% respectively. In conclusion, The application of calcium fertilizer is beneficial to improve the agronomic characteristics of peanut in acid soil, promote the accumulation of dry matter, improve agronomic characteristics, and accelerate the accumulation of calcium in the pod. The results of this study provided a theoretical basis for the improvement of calcium nutrition status of peanut in calcium-deficient soil.
To explore the impact of annual planting patterns of winter wheat summer corn and summer peanut on greenhouse gas emissions and carbon footprint in farmland, 3 crop rotation planting methods were set up: winter wheat summer corn, winter wheat summer peanut, and winter wheat summer corn and summer peanut. Among them, the intercropping of summer corn and summer peanut was 3∶4 (intercropped corn peanut row ratio of 3∶4), 3∶6 (intercropped corn peanut row ratio of 3∶6), and 6∶8 (intercropped corn peanut row ratio of 6∶8), the annual greenhouse gas emissions and carbon footprint characteristics of farmland were studied through field experiments. Results showed that the intercropping mode of summer corn and summer peanut could reduce greenhouse gas emissions in farmland, compared with corn monoculture, the average emission fluxes of soil CO2 and N2O decreased by 10.24%-18.75% and 10.78%-23.93%, respectively, and the total emission decreased by 8.30%-19.12% and 14.09%-26.81%, respectively. Intercropping reduced greenhouse gas emissions from subsequent winter wheat crops (under rotation mode), resulting in 3.79% decrease in soil CO2 emissions and 3.84% decrease in total emissions compared to corn monoculture treatment. Soil N2O emission flux decreased by 16.80% and the total emission decreased by 17.66%; the total amount of CH4 emissions from soil showed a "sink" phenomenon. In addition, the main source of carbon footprint in monoculture corn production was nitrogen fertilizer, accounting for 49.13% of the total emissions; the main sources of carbon footprint in monoculture peanut production were nitrogen fertilizer and plastic film, accounting for 23.77% and 26.06% of total emissions, respectively; the main sources of carbon footprint under intercropping mode were nitrogen fertilizer, diesel, and plastic film, accounting for 31.50%, 16.74%, and 17.92% of the total emissions, respectively. The intercropping mode increased the carbon emission efficiency of subsequent wheat crops, reduced the global warming potential, and greenhouse gas emission intensity. In summary, the annual planting model of winter wheat summer corn and summer peanut (intercropped corn peanut row ratio of 3∶6) could reduce carbon emissions from farmland and carbon footprint in crop production, and was beneficial for ecology.
For well production layout and high-yield of peanut, meteorological effects were investigated. For exploring the correlation between cultivation habitat and peanut yield, 9 peanuts (Arachis spp.) were planted in 7 different ecological regions of Yunnan for 2 years. The effects of meteorological factors on peanut agronomic traits and yield were analyzed by ANOVA, correlation analysis and path analysis. Results showed that temperature and accumulated temperature, peanut number of fruiting, shelling percentage and yield from Dehong, Binchuan, Dongchuan, Lincang and Yanjin were higher, which could be desirable areas for planting peanuts. Variance analysis results showed that growth and yield were affected by genotype and environmental factors. Higher temperature and accumulated temperature were conducive to shortening the podding stage, and then shortening the whole growth period. The higher the temperature, the higher the aboveground part, the higher the number of fruits per plant and the number of full fruits, and at the same time increased 100-fruit weight and 100-kernel weight, thereby increased the yield. But the long light time and the large temperature difference between day and night were not conducive to the growth and shoot branching.
In order to explore the development of peanut breeding in China, source distribution, breeding methods, yield, quality and other related characteristics of 587 peanut varieties registered during 2020-2023 were statistically analyzed. Results showed that 587 peanut varieties were mainly from North China, South China and the middle- and lower-reaches of the Yangtze River, of which Shandong and Henan provinces accounted for 53.83% of the total, and the breeding units were mainly scientific research institutes, accounting for 71.72%. The main breeding method was hybridization. The average growth period of peanut was 122.0 d; pod and seed yields were 4721.5 kg/hm2 and 3342.9 kg/hm2 respectively; 100-pod weight and 100-seed weight were 200.7 g and 81.0 g respectively; the full Pod per plant was 16.8; pod yield, seed yield and full Pod per plant decreased by years with the registration time. In terms of quality, coefficient of variation of oleic acid content (29.91%) was the largest, and oil content (6.03%) was the smallest. There were 215, 73 and 55 varieties with oleic acid content ≥75%, oil content ≥ 55% and protein content ≥ 28%, respectively. By cluster analysis, peanut varieties were divided into 3 groups: high yield, small grain and early maturity with the Euclidean distance as 12.
The batch selection of peanut cross combination study was carried out to provide theoretical guidance for the efficient breeding of new peanut varieties with high yield. Genomic selection analysis of 220 peanut germplasm resources was conducted using phenotypic data of single plant productivity and 100-pod weight at multiple locations for many years and re-sequencing data with depth of 10. Results showed that the phenotypic data were normally distributed, after genome data control, a total of 527 469 high-quality SNP （single nucleotide polymorphism） sites were obtained. The estimated breeding values of single plant productivity and 100-pod weight were calculated by GBLUP （genomic best linear unbiased prediction） model based on phenotypic data. The estimated breeding values were standardized, and the weights of single plant productivity and 100-pod weight were 70% and 30%, respectively, to obtain the comprehensive breeding index of peanut germplasm individuals. There were 190 hybrid combinations of the top 20 materials which showed comprehensive breeding values, and the comprehensive breeding index of any two combinations were calculated. The coefficient of parentage between each two materials was calculated using G matrix based on the genome data. Standardize the comprehensive breeding index of combination and coefficient of parentage, assign 80% and 20% weights respectively to calculate the comprehensive score of the combination. According to the ranking of the comprehensive score of the combination, we could select the parent directly to set hybrid combination. In conclusion, the germplasm materials derived from the combination Kainong30 × Kaixuan016 are suitable for high-yield parents. Genomic selection can efficiently and accurately calculate the ranking among combinations to select the parents and to make cross combinations in batches, improving the breeding efficiency rapidly.
