喀斯特地区春玉米套作夏大豆下作物产量和农田碳贮量对有机肥与化肥配施的响应

Effect of organic manure and chemical fertilizer combined application on crop yield and field carbon storage under spring maize intercropped with summer soybean in karst region

【目的】研究不同种类有机肥与化肥配施对喀斯特地区农田碳贮量和作物产量的影响,为喀斯特地区有机肥资源合理利用,增加作物产量和农田碳贮量,提高和稳定土地生产力提供参考。【方法】田间试验采用春玉米套作夏大豆的种植模式,各处理按照N、P、K含量相同原则,两种作物均设不施肥(CK)、单施化肥(NP)、50%秸秆+50%化肥(JG)、50%牛粪+50%化肥(NF)、50%滤泥+50%化肥(LN)和50%甘蔗灰+50%化肥(GZ)等6个处理。玉米施肥量为N 200.0 kg/ha、P2O560.0 kg/ha和K2O 100.0 kg/ha,大豆施肥量为N 22.5 kg/ha、P2O540.0 kg/ha和K2O 50.0 kg/ha,测定作物秸秆生物量、籽粒产量、不同部位碳含量和土壤有机碳含量及估算农田碳贮量。【结果】与CK相比,施肥能有效增加玉米秸秆生物量和籽粒产量。其中,JG处理玉米秸秆生物量提高最明显,GZ处理春玉米产量最高,但各施肥处理间玉米籽粒产量差异均不显著(P>0.05,下同);2012和2013年NP处理均显著提高大豆籽粒产量(P<0.05,下同),但与JG和NF处理差异不显著。各处理间土壤有机碳含量差异不显著;作物固碳量各施肥处理均显著高于CK,2012年NP处理效果最明显,且显著高于JG和NF,2013年各施肥处理间差异不显著;NF和LN处理显著提高农田碳贮量,其中以NF处理效果最佳。【结论】喀斯特地区春玉米套作夏大豆种植模式下,50%甘蔗灰+50%化肥处理玉米产量最高,50%牛粪+50%化肥是增加其农田碳贮量的最佳方案。

[Objective]The effects of combined application of different organic manures and chemical fertilizers on field carbon storage and crop yield in karst region were investigated, in order to provide technical references for rationally using organic resources in the karst region, increasing farmland carbon storage and crop yield, and improving and stabilizing land productivity. [Method]The field experiments were carried out by using spring maize-summer soybean intercropping pattern, which included six treatments viz., no fertilizer （CK）, single chemical fertilizer（NP）,50% corn stalk＋ 50% chemical fertilizer（JG）, 50% cattle manure＋50% chemical fertilizer（NF）, 50% filtered mud＋50% chemical fertilizer （LN） and 50% sugarcane ash＋50% chemical fertilizer （GZ）. The amount of fertilizer for maize was N 200.0 kg/ha, P2O5 60.0 kg/ha and K2O 100.0 kg/ha, the amount of fertilizer for soybean was N 22.5 kg/ha, P2O5 40.0 kg/ha and K2O 50.0 kg/ha. Then, the crop straw biomass, grain yield, carbon contents in different parts of crops and soil organic carbon （SOC） were determined, and the field carbon storage was estimated. [Result]The results showed that, compared with CK, the fertilization significantly increased straw biomass and grain yield of maize. Among all fertilization treatments, JG treatment could most obviously increase maize straw biomass and grain yield, there was non-significant difference in grain yield between every two fertilization treatments. As for soybean, the NP treatment could significantly improve soybean grain yield in 2012 and 2013, while non-significant difference was found between JG and NF treatments. Furthermore, there was no significant difference in soil carbon storage between every two fertilization treatments, and the crop carbon sequestration of every. fertilization treatment was significantly higher than that of CK. Above all, NP treatment had most significant improving effect in 2012, which was significantly higher than JG and NF treatments; and there was non-significant difference between every two fertilization treatments in 2015. Besides, the NF and LN treatments improved field carbon storage significantly, especially NF treatment with the best improving effect. [ Conclusion ]The combined application of 50% sugarcane ash and 50% chemical fertilizer has the most significant improving effect on grain yield of spring maize under intercropping model. And the combined application of 50% cattle manure and 50% chemical fertilizer is the optimal solution to increase farmland carbon storage.