减氮配施炭基肥对棉田土壤养分、氮素利用率及产量的影响

针对新疆覆膜滴灌棉田生产中土壤有机质含量低和氮肥利用率不高问题，研究氮肥减量下炭基肥对棉田土壤养分、棉花产量和氮素利用效率的影响。试验于2018年在新疆石河子121团炮台土壤改良试验站进行，设置不施氮肥（T1）、减氮施肥（T2）、施炭基肥（T3）、常规施肥（T4）4个处理。结果表明：施肥处理显著提高土壤全氮、碱解氮、有效磷含量，T3处理土壤全氮、有机质、碱解氮、有效磷含量最高。不同施肥处理对棉花产量和产量构成有显著影响，同等施氮量下，T3较T2处理产量提高5.2%；从棉花单株结铃数和单铃质量可以看出，T3＞T4＞T2>T1，与产量变化趋势相同。通过氮素投入量、氮素吸收量、产量以及干物质累积量分析棉花氮素利用率和氮肥产量贡献率发现，T3处理棉田氮吸收量最高，氮素利用率为55.1%，氮肥产量贡献率为31.9%，其次为T4和T2处理。综上，在新疆覆膜滴灌棉田采用炭基肥方式(T3)进行氮肥减施15%可保持棉田产量稳定提高氮素利用效率的目标，该研究结果可为新疆棉花化肥减施增效提供数据支撑。

Effect of Biochar-based Compound Fertilizer on Soil Nutrients and Cotton Yield in Irrigated Sandy Soil under Nitrogen Reduction Condition

Aiming at low content of soil organic matter and low use efficiency of nitrogen fertilizer in cotton field under mulching drip irrigation in Xinjiang, the effect of biochar-based fertilizer deriving from cotton straw fertilizer on soil nutrient, cotton yield structure and nitrogen utilization efficiency in cotton field was studied in this paper.In 2018, an experiment was conducted at Paotai Experimental Station of Regiment 121 in Shihezi Reclamation Area in Xinjiang. Cotton under drip mulching was taken as material and four treatments were set up, namely, no nitrogen application (T1), conventional nitrogen reduction treatment (T2), biochar-based nitrogen reduction treatment (T3) and conventional fertilization (T4).The results showed that fertilization treatment increased the contents of total nitrogen, alkali-hydrolyzed nitrogen and available phosphorus in the soil, in which the contents of total nitrogen, organic matter, alkali-hydrolyzed nitrogen and available phosphorus in the soil were the highest under T3 treatment , while the content of available potassium under each treatment had no significant difference.Different fertilization treatments had significant effects on the yield and yield composition of cotton. Under the same nitrogen application amount, the yield of T3 increased by 5.2% compared with T2 (P<0.05).From the boll number and boll mass per plant of cotton,T3> T4>T2>T1 had same change trend in the yield. By analyzing nitrogen input, nitrogen absorption, yield and dry matter accumulation of cotton nitrogen utilization rate and nitrogen fertilizer yield contribution rate, we found that T3 treatment with 15% nitrogen reduction by biochar-based fertilizer had the highest nitrogen absorption rate (P<0.05), the nitrogen utilization was 55.1%, nitrogen contribution rate to yield was 31.9%, followed by T4 and T2 treatment. In conclusion, the 15% reduction of nitrogen application by carbon-based fertilizerin cotton field under mulched drip irrigation can achieve the goal of stable yield and improvement of nitrogen utilization efficiency.