稻田冬种黑麦草对饲草生产和土壤微生物效应的影响(简报)

研究了2005-2006年湖南双季稻区,6种不同土质的稻田土壤在晚稻收获后免耕种植黑麦草,其生产性能和土壤微生物量碳、氮的变化。结果表明,6种土壤都比较适宜冬季黑麦草生产,黑麦草总干物质产量河沙泥田(11.3)>紫泥田(11.1)>灰泥田(10.6)>麻沙泥(10.5)>红泥田(9.75)>黄泥田(9.64 t/hm2)。粗蛋白含量为12%~15%,黑麦草全年粗蛋白质总产量在河沙泥田最高,为1.53 t/hm2,各处理黑麦草可消化干物质采食量均大于60%,各处理黑麦草的相对饲用价值均明显大于100%。6种土壤冬季种植黑麦草后,土壤微生物量碳(SMBC)和土壤微生物量氮(SMBN)变化为,除灰泥田外,冬种黑麦草处理均大于冬闲田,其中在河沙泥田增加的最高。稻田冬种黑麦草不仅能产生大量的优质牧草,对改善稻田土壤生态环境,提高稻田耕地质量有一定的积极作用。

Effects of winter ryegrass growth for forages production and soil microbial activity in six paddy soils

The total amount of winter fallow areas have increased in south China in recent years.This not only causes enormous waste of resources and energies,but also affects paddy soil qualities and farming environments. Winter ryegrass is essential to improve soil productivity and winter forage yields.The purposes of this study were to investigate the effects of winter ryegrass on forage development and the changes of soil microbial biomass carbon and nitrogen in six different types of paddy soils in south China.Winter ryegrass dry matter was significantly different in different types of paddy soils.Ryegrass biomass was in the order alluvial,sandy soil(11.3)>purple clayey soil(11.1)>grey clayey soil(10.6)>granitic sandy soil(10.5)>red clayey soil(9.75)>yellow clayey soil(9.64 t/hm2).Ryegrass crude protein(CP) content was 12%-15% and relative feed value(RFV)>100% was in all soil types.The changes of soil microbial biomass carbon(SMBC) and soil microbial biomass nitrogen(SMBN) were significant between winter ryegrass and winter fallow treatment in the six different paddy soils.Winter ryegrass increased soil microbial quotient,especially in alluvial sandy soil while winter fallow developed winter ryegrass production,improving soil properties and increasing paddyfield ecosystem functioning.