Abstract:
Objective The aims were to study the compounded fertilizer respectively combined with commercial organic fertilizer, humic acid-soluble organic fertilizer, and calcium oxide impact on the number of culturable microorganisms, soil enzyme activities, soil nutrient contents, peanut plant growth, and pod yield of continuous cropping peanut, in order to provide a theoretical basis for rational fertilization for peanut plantation.
Method The experiment was carried out on peanut plots with continuous cropping for 3 years. Applied compound fertilizer 600 kg hm−2 (T0) was used as the control. On this basis, added 600 kg hm−2 commercial organic fertilizer was treatment 1 (T1), added 75 L hm−2 humic acid containing organic water-soluble fertilizer was treatment 2 (T2), added 600 kg hm−2 calcium oxide was treatment 3 (T3). Under different treatments, respective determination of the number of soil microorganisms, soil enzyme activity, soil nutrient contents, peanut plant growth, and pod yield.
Result Compared to the control, organic materials (T1, T2) significantly increased the total number of culturable microorganisms during the whole growth periods, and the ratios of culturable bacteria to culturable fungi immaturity stage were from 48.59 (T0) to 58.93 (T1) and 59.94 (T2). Therefore, the transformation of soil to "fungi advantage" was mitigated. T1 and T2 also significantly increased soil enzyme activities, soil nutrient contents and promoted peanut plant growth and pod yield. Comparison between two organic materials, T2 increased the pod yield by 11.17%, and the effect of alleviating peanut continuous cropping disorder was better. Under the T3, there was no significant difference in soil indices during the whole growth period of peanut. However, the pod yield increased by 5.12% in the addition of calcium-oxide, and the weights of 100 pods & kernel significantly increased too.
Conclusion Applied compound fertilizer 600 kg hm−2 combined with 75 L hm−2 humic acid containing organic water-soluble fertilizer (T2) has the best effect of alleviating peanut continuous cropping disorder. Under this treatment, the soil microbial activities, soil enzyme activities, soil nutrient contents, and peanut pod yield were increased significantly.