稻田施氮水平对两种水稻热值变化特征影响

对两种水稻类型（早稻，晚稻）在不同氮素水平下植株的热值动态进行了分析。结果表明，水稻植株的热值不仅因品种，器官而存在着差异，而且随着水稻生长发育的进程不同也存在着差异。两种水稻的热值最低出现在小花分化期，最大值出现在分蘖期或开花灌浆时期。不同氮素水平对水稻热值的影响规律为，随着氮素水平的增加，水稻各种组织器官的热值也增加，同一器官下，高氮素水平下的水稻组织热值高于低氮下组织的热值，不同器官热值（根，茎，叶，穗）之间在相同及不同氮素水平下存在显著差异。通过分析表明，没有氮素投入下的两种水稻基础热值为16979J/g，早稻每增加1kg/hm^2N，可以提高植株热值1.72J/g，晚稻每增加1kg/hm^2N，可以提高植株热值1.24J/g，这说明，氮素使用对早稻的热值效应影响要大于晚稻。因此，在运用热值指标进行能量分析时，必须考虑氮素使用水平对热值的影响。

The Quantitative Analysis of the Caloric Value Dynamics of Two Rice Varieties Under Different Nitrogen Application Levels

This paper presents an analysis of the quantitative caloric energy characteristics and the dynamic variation of two rice varieties under different N levels in paddy fields in Hangzhou, Zhejiang Province, China. Field experiments were conducted at the Experimental Farm of Zhejiang University, Hua-Jia-Chi Campus, Hangzhou (latitude 30.2° N, longitude 120° E), China at 43.2m above sea level. The experimental site had an area of 1085.5 m 2. The early crop rice, Jiayu 948, was sown on 1 st April, and transpl...