不同氮、磷、钾肥用量对玉米源、库干物质积累动态变化的影响

本研究采用田间小区的试验方法研究了不同氮、磷、钾用量下玉米各组分的干物质积累及其随时间的动态变化规律。结果表明,不同氮、磷、钾肥用量下玉米的各组分干物质积累随生育期的延续呈现有规律的动态变化:叶片、茎秆、营养体干物质积累自拔节期后呈直线上升,至灌浆期干物质积累达到最大值,之后便呈缓慢下降趋势;籽粒的干物质积累在灌浆期之前缓慢增加,之后呈直线上升;总生物产量在苗期缓慢增长,中期呈直线上升,到了后期由于营养体干物质的下降以及籽粒干物质的显著上升,也稳定增长。营养体、籽粒干物质和总生物产量的积累随时间的动态变化,均可用Logistic方程Y=a/(1+bexp(ct))来描述;在各个氮、磷、钾处理中,以N240、P225、K240处理各组分干物质积累最大速率较大,出现日期较早。籽粒和总生物产量之间的关系可用回归方程Y=exp(a+bx)描述。在氮、磷、钾各用量下,氮以N240、磷以P225、钾以K240处理籽粒产量最高,收获系数最大,因此比较适宜的N、P2O5、K2O用量分别为240、150、240 kg hm-2。

Dynamics Changes of Dry Matter Accumulation of Maize as Affected by Different Quantity of Nitrogen and Phosphorus and Potassium

Field trial was conducted to study the dynamic changes of dry matter accumulation of maize by supplying different N,P and K.Results showed that the dry matter accumulation of leaves,stems and vegetative organs increased linearly from the end of elongation stage to the maximum at filling stage,and then decreased gradually.Grain weight increased slowly before filling stage,but increased sharply after filling stage.Total biomass increased slowly at seeding stage,but increased rapidly at middle stage.Up to the late stage of growth there was still a stable increase in the dry matter accumulation of leaves,but the stems decreased slowly and the grain weight increased sharply.The results of dynamic changes of dry matter accumulations for vegetative organs,grain weight and total biomass could be expressed through formula: Y=K/(1 aexp(bt).The maximum accumulation rate of different components was larger and earlier at the N240,P225 and K240 treatment than at other treatments.The relationship between grain yield and total biomass could be expressed through formula: Y=exp(a bx).Hence,the suitable applying rate of N,P and K was 240,225 and 240 respectively.