亚热带单季稻区紫云英不同翻压量下有机碳和养分释放特征

A study on organic carbon and nutrient releasing characteristics of different Astragalus sinicus manure use levels in a single cropping region of subtropical China

在70%田间持水量以及近自然气温条件下,利用网袋法模拟亚热带单季稻区紫云英盛花期不同翻压量下的腐解和养分释放特征。结果表明,不同翻压量下紫云英干物质腐解速率均为前20d最高,至60d后进入缓慢腐解阶段。腐解至90d,低、中、高翻压量下的干物质累积腐解率分别达78.7%,76.0%,71.2%。紫云英碳、氮、磷、钾累积腐解率与腐解时间呈幂函数关系,拟合方程分别为Y=13.4246 X0.4391(P<0.01),Y=14.0314 X0.4208(P<0.01),Y=3.5458 X0.7037(P<0.01),Y=15.7784 X0.4213(P<0.01)。紫云英有机碳与养分前20d累积释放率与全腐解期累积释放率均表现为钾>碳>氮>磷,且随着翻压量增加,有机碳及养分累积释放率呈逐渐降低趋势。

Organic carbon and nutrient release characteristics of different Astragalus sinicus manure use levels applied at the bloom stage in a single cropping region of subtropical China were studied using manured soil in net bags with a field moisture capacity of 70% and at ambient temperature.The speed of decomposition reached a peak within 20 days,but was low after the 60th day.On the 90th day,accumulated decomposition rates of dry material represented low（equated to 15 000 kg/ha） to high（equated to 45 000 kg/ha） manure use levels were 78.7%,76.0% and 71.2%,respectively.Release of C,N,P,and K could be calculated with the following power function formulas： Y=13.4246X0.4391（P0.01）,Y=14.0314X0.4208（P0.01）,Y=3.5458X0.7037（P0.01）,Y=15.7784X0.4213（P0.01）.Accumulated release rates of carbon and nutrient were： KCNP in the first 20 days as well as during all decomposition periods.Moreover,accumulated release rates of carbon and nutrient both steadily decreased with an increase of A.sinicus manure levels.