控释肥对稻草覆盖红壤花生产量及土壤有效氮平衡的影响

采用田间试验研究了稻草覆盖等量施肥条件下,配施控释肥(controlled release fertilizer,CRF)20%(MF20)、40%(MF40)、60%(MF60)、传统一次施肥(MF0)、不施肥(CK1)以及无覆盖分次施肥(CK2)对花生产量、氮素吸收利用及土壤有效氮平衡的影响。结果表明:在一次性施肥条件下,配施20%控释肥(MF20)处理,花生产量最佳,达到分次施肥产量水平,过多配施控释肥将影响产量;氮素表观利用率随控释肥配施比例的增大先增加后降低,MF20处理氮肥表观利用率最高(57.39%),分别较MF0和CK2处理增加20.94%和3.84%。MF20处理氮肥农学利用率、偏生产力、氮素吸收效率以及花生吸氮量均最高,但随着控释肥配施比例的增加均呈降低趋势,而氮素表观损失率的变化趋势相反。土壤氮盈余则随着控释肥比例增大而明显增加。综合有效氮平衡,本试验的土壤条件下,减氮施肥技术对挖掘花生自身固氮潜力、提高肥料利用率、保证红壤区花生高产稳产等具有重要的意义。

Effect of controlled release fertilizer on yield of peanut and balance of availiable nitrogen in upland red soil mulched with rice straw

To explore effect of controlled release fertilizer (CRF) on yield of peanut and balance of available N in red soil mulched with rice straw, a field experiment designed to have six treatments, i.e. Treatment MF20 (M stands for mulching, F for fertilizer and the number for the proportion CRF accounted for of the total fertilizer applied, here 20%), Treatment MF40, Treatment MF60, Treatment MF0, Treatment CK1 (mulching only) and CK2 (no mulching in addition to split application of fertilizer), was conducted. Results show that Treatment MF20 was the highest, and similar to Treatment CK2, in peanut yield, show a declining trend with increasing proportion of CRF. Treatment MF20 was also the highest in apparent N utilization efficiency, reaching up to 57.39% and being 20.94% and 3.84% higher than Treatment MF0 and Treatment CK2, respectively, and in N agronomic use efficiency, partial productivity, N uptake efficiency and total nitrogen uptake, as well. All the proceeding indices declined with rising proportion of CRF, once beyond 20%, but the index of apparent N loss rate displayed a reverse trend. (ANLR) and the index of soil N surplus did, too. Based on the balance of soil available nitrogen in the test soil, the technique of halving the nitrogen application rate is an effective measure to tap the N fixing potential of the crop per se, to improve nitrogen fertilizer utilization efficiency while ensuring a stable high yield of peanut in the upland red soil mulched with rice straw.