不同秸秆还田模式对风沙土玉米生育特性及土壤活性碳、氮的影响

Effects of Straw Incorporation Modes on Characteristics of Maize Growth and Labile Organic Carbon and Nitrogen in Sandy Soil

研究设计两年风沙土玉米盆栽试验,设置五个处理:秸秆不还田(CK)、秸秆春还田配合还田灌溉一次(SI),秸秆春还田配施菌剂及还田灌溉一次(SIB),秸秆秋还田配合还田灌溉两次,还田一次,上冻前一次(FI),秸秆秋还田配施菌剂及还田灌溉两次(FIB),其他田间管理相同,所有处理均常规施肥,通过分析作物苗期的生物量、根冠比及产量等植株信息,以及地下土壤部分可溶性碳、氮等指标,探讨秋季秸秆坐水还田模式对风沙土土壤养分的影响及对当季作物生长发育的贡献。结果表明:(1)与常规施肥处理CK相比,秋季坐水还田FIB处理植株鲜重增加了49.82%,干重增加了45.19%,粒重增加了131.74%;(2)植株苗期,与常规施肥处理CK相比,FIB处理地下部分增加了70.32%,根冠比增加了63.50%,存活率也大幅度提高,达到100%;(3)在植株整个生育期内,FIB处理从拔节期到大喇叭口期植株茎粗生长速度最快,高度增级幅度最大达22.08%;(4)在大喇叭口期,与常规施肥处理CK相比,FIB处理土壤微生物碳增加了103.98%,土壤微生物氮增加了312.11%,土壤可溶性碳增加了3.93%,土壤可溶性氮略有下降。可见,秸秆经秋季坐水还田冬季冻融作用后,比常规还田和菌剂配施还田腐熟更快,更有利于提高风沙土土壤养分以及作物的生长发育。

A pot experiment for twoyearswas carried out in sandy soil to study the effects of straws on soil nutrients and labile organic carbon and on crop growth and development. Five treatments were chosen in this paper： no straw （CK）, straw returning combined with irrigation in spring （SI）, straw returning combined with irrigation and bactericide in spring （SIB）, straw returning combined with irrigation in fall （FI）, straw returning combined with irrigation and bactericide in fall （FIB）. Equal amount of nitrogen （N）, phosphorus （P）, and potassium （K） fertilizers were used as base fertilizer in all treatments. Soil samples were collected from soil plough layer duringthe maize growth period. After the crops were harvested, the contents of nutrients, labile organic carbon and microbial biomass carbon were analyzed. The plant properties and corn growth indices were calculated during the maize growth period. Results showed that compared with CK treatment, FIB treatment increased plant fresh weight, plant dry matter weight andgrain weight, respectively, by 49.82%, 45.19% and 131.74%. At maize seedling stage, FIB treatment increased dry weight of root and the ratio of root to shoot, respectively,by 70.32% and 63.50% and the germination rate reached tolO0%. From the elongation stage to the flare opening stage, stem diameter was remarkably higher 22.08% in FIB treatment than in the other treatments. At the flare opening stage, FIB treatment increased microbial biomass carbon, labile organic carbon, microbial biomass nitrogen by 103.98%, 3.93% and 312.11%, respectively, compared with CK treatment. These results indicated that the effect of freezing and thawing, straw returning combined with irrigation was beneficial for improving soil fertility and provided a suitable soil environment for crop growth.