配方施肥及氮肥后移对单季稻氮素累积和利用率的影响

为研究配方施肥及氮肥后移对水稻产量和氮肥利用率的影响,采用田间试验的方法,对比分析了常规施肥与配方施肥及氮肥后移条件下水稻产量、氮素累积量和氮肥利用率的差异。结果表明:1)与常规施肥相比,配方施肥使水稻成熟期叶片氮素总累积量和净累积量分别提高了9.43%~29.25%和8.45%~35.21%;水稻产量增加了1.16%~2.86%、氮肥利用率提高了10.12%~18.61%、产出与投入比增加了0.09%~3.8%。2)在相同施氮水平下,与PF1(基∶蘖∶穗=60%∶30%∶10%)处理相比,氮肥后移的PF2(基∶蘖∶穗=40%∶30%∶30%)处理使水稻成熟期叶片氮素总累积量和净累积量提高了17.24%和23.38%;水稻产量、氮肥利用率和产出与投入比分别提高了0.38%、7.06%和0.64%。3)水稻产量和氮肥利用率分别与成熟期叶片全氮含量及氮素总累积量存在显著或极显著正相关,相关系数(R)在0.85*~0.99**之间。这表明,配方施肥和氮肥后移可通过增加水稻生育期叶片氮素含量和累积量,提高水稻产量和氮肥利用率,增加经济效益。

Nitrogen accumulation and use efficiency of single rice under soil testing and nitrogen distribution

Field experiments relative to soil testing and N distribution during rice growth period (PF) were set up in order to improve rice yield and nitrogen (N) use efficiency.The results showed that the N accumulation of leaves in soil testing rice plant at mature stage was higher than of conventional fertilization rice.Moreover,rice yield,N use efficiency and the ratio of input to output in the soil testing rice were 1.16%-2.86%,10.12%-18.61% and 0.09%-3.8% higher than those of conventional fertilization rice respectively.The accumulated nitrogen of leaves in rice plant at mature stage were higher in PF2 (basal N:tiller N:panicle N = 40%:30%:30%) than that of PF1 (basal N:tiller N:panicle N = 60%:30%:10%).Meanwhile,rice yield,N use efficiency and the ratio of input to output of PF2 rice increased by 0.38%,7.06% and 0.64% respectively compared with PF1.Both rice yields and N use efficiency were significantly correlated with N concentration and the total accumulated N in rice leaves at mature stage,and the correlation efficiencies (R) ranged from 0.85^* to 0.99^**.It was evident that soil testing and more N at late stage of rice significantly increased the N accumulation and ues efficiency, and rice yield and income as well.