养分专家系统在双季常规稻模式下的减氮效应

Application and evaluation of nutrient expert system in double-cropping conventional rice model

近年来,双季稻区的常规稻种植规模在不断扩大。同时,氮肥施用过多也是生产中的突出问题,因此,在双季常规稻种植模式下养分专家系统推荐施肥的减氮效应研究具有重要意义。试验于2019和2020年在江西省进贤县温圳镇进行,早晚稻均为常规稻品种,分别为江早361和湘晚籼12号,开展双季种植,在养分专家推荐施肥(NE)的基础上,设置不施氮肥处理(NE-100%N)、氮肥减量25%和50%(NE-25%N和NE-50%N)、氮肥增量25%和50%(NE+25%N和NE+50%N)共6个处理,测定水稻产量、植株氮素养分吸收量、氮肥利用率等指标。结果显示,两年早、晚稻产量及氮肥产量反应均为养分专家系统推荐施氮量的NE处理最高,较NE-100%N和NE-50%N处理显著增产11.6%~59.3%,随施氮量的增加,至NE处理时产量达到最高,继续增加则水稻产量有降低趋势。进一步进行拟合方程表明,产量和施氮量之间呈极显著一元二次抛物线关系,两年NE处理早、晚稻施氮量较最大施氮量分别降低13.7%~18.2%和6.7%~12.5%,而产量均较最大施氮量对应产量略高。氮素养分吸收量随施氮量的增加,在NE处理时达到最高,早、晚稻两年平均氮素吸收量较其他处理分别显著提高9.5%~105.7%和7.0%~88.0%。而NE处理的早、晚稻平均氮肥吸收利用率较其余处理两年增幅分别为14.7%~147.0%和8.9%~155.0%,平均农学效率较NE-50%N、NE-25%N处理均无显著差异,较其余处理两年增幅为27.9%~108.2%。综上,养分专家系统推荐氮肥用量可使双季常规稻增产,提高水稻植株的氮素养分吸收量以及氮肥利用率,同时达到减氮增效的目标,有利于科学指导双季常规稻的氮肥施用。

In recent years,the scale of conventional rice planting in the double-cropping rice area has been continuously expanding.At the same time,excessive application of nitrogen fertilizer is also a prominent problem in production.Therefore,it is of great significance to study the nitrogen reduction effect of fertilizer recommended by nutrient expert system in the double-cropping conventional rice planting mode.The experiment was carried out in Wenzhen Town,Jinxian County,Jiangxi Province in 2019 and 2020.Early and late rice varieties were conventional rice varieties,Jiangzao 361 and Xiangwanxian 12,respectively.A total of six treatments,including fertilizer recommended by nutrient experts(NE),no nitrogen fertilizer treatment(NE-100%N),nitrogen fertilizer reduction by 25%and 50%(NE-25%N and NE-50%N),nitrogen fertilizer increased by 25%and 50%(NE+25%N and NE+50%N)were set up,and rice yield,plant nitrogen,phosphorus and potassium nutrient uptake,nitrogen utilization efficiency and other indicators were measured.The results showed that the twoyear early and late rice yields and nitrogen fertilizer yield response were the highest in the NE treatment,which significantly increased the yield by 11.6%~59.3%compared with the NE-100%N and NE-50%N treatments.With the increase of the nitrogen amount,the yield reached the highest at the NE treatment,and when nitrogen continued to increase,the rice yield had a decreasing trend.Further calculation of the fitting equation showed that there was a very significant one-variable quadratic parabola relationship between yield and nitrogen application rate.Nitrogen application rates for early and late rice in the two-year NE treatment were reduced by 13.7%~18.2%and 6.7%~12.5%,respectively,compared with the optimal nitrogen rate,and the yield was slightly higher than the corresponding yield of the optimum nitrogen application rate.The nutrient uptake of nitrogen increased with the amount of nitrogen applied,and reached the highest in NE treatment.The two-year average nitrogen uptake of early and late rice was significantly increased by 9.5%~105.7%and 7.0%~88.0%compared with other treatments,respectively.The average nitrogen uptake efficiency of early and late rice with NE treatment increased by 14.7%~147.0%and 8.9%~155.0%,respectively,compared with the other treatments in two years.The average agronomic utilization of NE treatment had no significant difference than that of NE-50%N and NE-25%N treatments.,and the increase was 27.9%~108.2%compared with the other treatments in two years.In summary,the amount of nitrogen fertilizer recommended by nutrient expert system can increase the yield of double-cropping conventional rice,increase the nitrogen nutrient uptake of rice plants and the utilization of nitrogen fertilizer,and at the same time achieve the goal of reducing nitrogen and increasing efficiency,which is conducive to scientifically guiding the application of nitrogen fertilizer for double-cropping conventional rice.