长期隔年施磷对陇东旱塬作物产量和土壤肥力的影响

为探讨不同施肥方式对旱地土壤的培肥作用及增产效果,以1979-2019年在甘肃省陇东旱塬黑垆上土进行的长期定位施肥试验为基础,研究了不施肥料(CK)、单施氮肥(N)、氮磷肥配施(NP)、秸秆还田+氮磷肥配施(磷肥为隔年施用,施磷年份该处理记为SNP,不施磷年份记为SN)4种措施对作物产量、产量稳定性和可持续性以及土壤综合肥力的影响。结果表明,长期隔年施磷(SN)的春玉米和冬小麦产量分别较CK增加151.4%和159.2%,较长期施磷处理(SNP)增加8.6%和6.9%;SN的春玉米产量稳定性和可持续性均低于N和NP处理,而冬小麦产量稳定性和可持续性均优于N和NP处理;SN处理显著提高了耕层土壤综合肥力(IFI),其耕层土壤IFI值分别较CK、N和NP处理高25.5%、21.3%和6.1%,年际间变异强度高于CK和N处理。说明,在陇东旱塬黑垆土春玉米-冬小麦轮作体系下,采用秸秆还田+氮磷配施隔年施磷技术,既在减少50%化学磷肥投入的情况下仍能保证作物产量稳定和持续,并能有效提高耕层土壤综合肥力。

Effect of Long-term Phosphorus Application by Every Two Years on Crop Yield and Soil Fertility in Loess Plateau of East Gansu Province

In order to systematically study the effects of different fertilization methods on the soil fertility and the crop yield in dryland,a long-term fertilization experiment was conducted in the Loess Plateau of the east Gansu Province from 1979 to 2019. We studied the fertility effects on the yield,sustainability and soil fertility with four different treatments: no fertilizer(CK),single chemical nitrogen fertilizer(N),nitrogen-phosphorus fertilizer(NP),and straw + nitrogen-phosphorus fertilizer(SNP) with phosphorus application by every two years(SN for the interval year without phosphorus application). Compared with CK,the average yield of spring maize and winter wheat under the SN treatment was significantly increased by 151.4% and 159.2%,respectively. The yield of winter wheat and maize under SN treatment was 8.6% and 6.9% higher than that under SNP treatment. The stability and sustainability of yield index of maize under SN treatment were lower than those under N and NP treatments,whereas those of winter wheat under SN treatment were higher than those under N and NP treatments. Compared with CK,N and NP treatments,the soil integrated fertility index under SN treatment was significantly improved by 25.5%,21.3% and 6.1%,respectively.However,the intensity of inter-annual variation was higher than that of CK or N treatment. Straw returning + nitrogen and phosphorus application by every two years ensured the stable and sustainable crop yield and effectively improved the comprehensive fertility of soil,which is equivalent to reducing 50% of chemical phosphorus fertilizer input under the spring maize-winter wheat rotation system in the Loess Plateau of the east Gansu Province.