摘要
在集约化过程中的不同投入水平下,有机质等土壤肥力因素所起的作用不同。在不投入或低投入阶段,对产量的贡献份额相对较大;而高投入阶段对产量的贡献份额相对较小,人工投入作用较大,部分代替了土壤肥力的作用。沧州地区大部分中、高产田的土壤肥力指标非常相近,几乎没什么差异,产量的提高主要和人工投入量有关,即本区大部分中高产田有机质等肥力因素已不再是产量的限制因子。但一些低产田有机质等土壤肥力指标仍然较低,可能为产量的限制因子。
At the different levels of input during intensification the soil fertility such as the soil organic matter(SOM)has different roles.At the level of no input or low input it makes reletively great contribution to the yield.But,at the level of high input it's contribution becomes smaller and the role of input becomes more important and partially replaces the role of the soil fertility.On most of the middle and high yield fields in Cangzhou region Hebei Province,the indicators of the soil fertility shows no differ- ent.SOM,quick-acting phosphorus,and alkaline nitrogen is about 1%,8 mg·kg^(-1)and 35～40 mg·kg^(-1) or so respectively.The increase of yield is mainly related to quantity of input.That is to say,to most of the middle and high yield field in this area,the soil fertility such as SOM is no longer a limitting factor for present high yield.But,to some low yield fields,the indicators of the soil fertility such as SOM is still lower,It is a limitting factor of yied.
关键词
土壤肥力
集约高产
投入水平
soil fertility
input level
agricultural intensification
