长期配施有机肥对灌淤土春玉米产量及氮素利用的影响

为了寻求合理利用畜禽粪便资源与改善玉米氮素利用的有效措施,通过3a连续田间定位试验,研究有机肥替代部分化肥配施对玉米产量和氮素利用率的影响。结果表明:与CK相较,施用有机肥土壤pH值下降了0.59~0.86,土壤容重下降了8.05%~10.74%。有机无机配施(N1M1、N2M2)处理定位施肥3a后,土壤有机质含量年均分别增加0.86,0.44g/kg,土壤全氮含量年均分别增加0.09,0.06g/kg,土壤碱解氮含量年均分别增加4.74,3.68mg/kg,土壤速效磷含量年均分别增加6.62,5.35mg/kg,土壤速效钾含量年均分别增加8.46,6.66mg/kg。与常规N1处理比较,第3年N1M1、N2M2处理的产量分别提高了12.38%和13.43%,氮肥利用率分别提高了10.98%和16.20%,氮肥农学效率分别提高了4.65,10.50kg/kg,氮肥偏生产力分别提高了4.65,21.02kg/kg。因此,配施有机肥可降低土壤pH值和容重,显著提升土壤有机质和养分含量,对促进玉米产量和氮肥利用率具有积极作用,其中N2M2处理是协调作物产量和环境安全的合理选择。

Effects of Long-term Fertilization on Yield and Nitrogen Utilization of Spring Maize in Irrigation Silting Soils

In order to explore the effective measures that could make rational utilization of livestock manure and improve nitrogen utilization of maize,a three-year field experiment was conducted to evaluate the effects of combined applications of manure and chemical fertilizers on maize yield and nitrogen utilization in irrigation silting soils.The results showed that,compared to the no nitrogen fertilizer (CK),pH of soil treated with combined manure and chemical fertilizer decreased by 0.59 to 0.86,soil bulk density decreased by 8.05 ％ to 10.74％.Soil organic matter of combined application of organic manure and chemical fertilizer (N1M1,N2M2) was increased by 0.86 g/kg and 0.44 g/kg per year,respectively;total nitrogen concentration was increased by 0.09 g/kg and 0.06 g/kg per year,respectively;the concentration of alkali-hydrolyzable nitrogen was increased by 4.74 mg/kg and 3.68 mg/kg per year;plant-available phosphorus concentration was increased by 6.62 mg/kg and 5.35 mg/kg per year;plant-available potassium concentration was increased by 8.46 mg/ kg and 6.66 mg/kg per year.Compared to that in the conventional chemical nitrogen treatment (N1),maize yield was increased by 12.38％ and 13.43％ in the third year by the N1M1 and N2M2 treatment,respectively;the NUE was increased by 10.98％ and 16.20％;the AEN was increased by 4.65 kg/kg and 10.50 kg/kg;the PFPN was increased by 4.65 kg/kg and 21.02 kg/kg,respectively.Therefore,soil pH value and bulk density were all decreased in lowered chemical nitrogen combined with manure as compared to the conventional chemical nitrogen,soil organic matter and nutrient concentration were all significantly increased.Combined application of organic manure and chemical fertilizer had a positive effect on maize yield and nitrogen utilization.Applying chemical nitrogen at 168 kg/hm2 + manure nitrogen at 72 kg/hm2 could maintain maize yield and alleviate environmental pollution in irrigation silting soils of Ningxia.