Abstract:

Biogas slurry (BS), derived from pig dung and urine, was applied in a upland field of red soil in Yujiang of Jiangxi in a field experiment to explore effects of BS on yield, biomass and N, P accumulation at each growth stage, as well as fertilizer recovery rate of peanut. All the treatments, except CK,were the same in total N, P₂O₅ and K₂O input(120-90-135 kg·hm^-2). Results show that the peanut responded significantly in yield to combined application of BS and chemical fertilizer(CF), regardless of rate,with an increment of 44.50%-55.70% and 10.80%-19.40% as compared to CK and Treatment NPK, respectively. And Treatment BS30 was the highest in yield, reaching 3588 kg·hm^-2. Correlation analysis reveals that the relationship between yield(y) and BS input(x) fitted the equation of y=-1.1365x²+59.112x+2988.3(R²=0.98, P<0.01). Treatment BS30 was 7.29%-56.69%, 11.24%-100.44% and 9.33%-62.17% higher in plant biomass accumulation, 16.58%-77.53%, 4.99%-113.74% and 1.81%-58.58% higher in plant N accumulation and 4.99%-113.74%, 3.06%-127.18% and 12.56%-62.17%, higher in plant P accumulation than all the other treatments at the flowering, pod-bearing and harvesting stages, respectively. Besides, Treatment BS30 was 3.27%-23.89% and 2.72%-19.34%, too, in ratio of total N and total P in grains to total biomass N and P. Obviously, when biogas slurry is applied at 30% of the total N input, the crop will take up more readily available N and P from the soil at the flowering, pod-bearing and harvesting stages, while transporting more plant-absorbed N and P to grains. So the practice will significantly increase yield of the peanut crop and N and P recovery rates of the plants at various growth stages. It is, therefore, held that the practice is worth popularizing in red soil areas for peanut production.

Key words: biogas slurry, chemical fertilizer, yield, biomass accumulation, N, P accumulation, fertilizer recovery rate