Abstract:

To improve yield and economic benefit of the South China peanut production under sugarcane / peanut intercropping, field trials with 4 gradients of NPK fertilizers were conducted to investigate the fertilizer ratio on yield, NPK nutrient absorption and economic benefit. Results showed that the highest peanut yield and economic benefits could be obtained under 80 kg/hm² N, 70 kg/hm² P₂O₅, and 80-90 kg/hm² K₂O, and the harvest index and nutrient utilization rate are also higher. NP absorption in intercropped peanut increased with the NP fertilizer application, while excessive K fertilizer application inhibited K absorption by peanuts. The key period of dry matter accumulation and nutrient absorption of intercropped peanut was from anthesis needling to pod expansion. The dry matter accumulation of intercropped peanuts increased with NPK application. For each 1000 g dry matter forming, it needed to absorb and assimilate 17.7 g N, 1.7 g P₂O₅ and 11.3 g K₂O, with the absorption ratio as 10.4 : 1 : 6.6 （N : P₂O : K₂O）. The nutrient absorption ratio per 100 kg pods varied depending on NPK fertilizers ratio, as 6.83-7.98 kg N, 0.65-0.80 kg P₂O₅, and 4.10-5.32 kg K₂O. Therefore, the recommended N, P₂O₅ and K₂O application rate of intercropped peanut in South China with the best economic benefit was 80 kg/hm² N, 70 kg/hm² P₂O₅, and 80-90 kg/hm² K₂O.

Key words: intercropped peanut, N, P, K ratio, yield profit, nutrient utilization