土壤容重对高产玉米根系生长的影响及调控研究

不同土壤容重不同,其稳定性也不同。土壤容重的变化会引起土壤调节水、气、热能力的变化,提高土壤的自动调节能力可以使土壤肥力水平得以提高并满足植物对生长因子的持续需求。为研究土壤物理性质对玉米高产稳产的影响机理,以耕地棕壤为试验材料,采用盆栽方法,研究不同容重对玉米根系生长指标的影响,并进一步研究了施用不同有机肥量及模拟不同耕作深度对玉米根系生长的调控效果。结果表明:在设计容重范围内,容重增加,根系生长指标都表现为下降,容重大于1.2 g/m3时,不同处理根系生长指标差异显著;当容重大于1.3 g/cm3时,不同处理根系活力差异显著。施用有机肥对高容重土壤调控效果更好,有机质含量为4%与5%的处理差异减小,低容重土壤在所设计的有机质水平内调控效果也都较好。耕层厚度增加可以提高根系生长参数,但与对照相比,差异不显著。所以,对于紧实结构性较差的土壤,改善其调节能力应该通过增施有机肥的方法,紧实结构较好的土壤考虑使用耕翻的办法。

Effects of Bulk Density on Root Growth of High Yield Maize and Their Regulation

Soil bulk density is one of the important soil physical properties.Different soil with different soil bulk density and stability,at the same time,soil regulation ability of soil-water,soil-gas,soil-heat capacity changed with unstability of soil bulk density.It can improve soil fertility degree and the continuing demand factors of plant growth if the soil′s automatically adaptational ability was enhanced,therefore,it is necessary to research how soil bulk density vary and how to regulate and control it.In order to study the mechanism of the impact of soil physical properties on high and stable yield of maize,this paper,with cultivated brown soil and pot experiment,studied the effect of soil bulk density on maize root growth parameters(root length,root area,root volume),furthermore,it studied the result of regulation by application of organic fertilizer and simulation of different tillage depth in shenyang agricultural university.The results showed that soil bulk density had distinct effect on maize root growth,maize root growth index showed downward with increased soil bulk density at the designing range of bulk density.When soil bulk density changed from 1.2 g/cm3 to 1.3 g/cm3,the maize root growth parameters were distinct difference among all treatments(P<0.01),and it was not obvious influence on maize root growth when soil bulk density over 1.3 g/cm3,meanwhile,maize root activity were significant distinction when soil bulk density exceed 1.3 g/cm3,it showed decrease with soil bulk density growing(P<0.01).Organic fertilizer is more effective to high soil bulk density compared with low ones,treatment effect were not obvious when organic fertilizer level were 4% and 5%,while it was consecutive obvious for low soil bulk density at the designing range of soil bulk density,the reason was organic fertilizer significantly reduced the soil bulk density,at the same time it efficiently increased the soil porosity,water capacity and air porosity.With the thickness of tillage increased,plant height,stem diameter,total root length,chlorophyll a and yields of maize were decrease,but effect was not significantly distinct.Index of maize growth was not changed when the top layer thickness adjustment to 30 cm to 40 cm,adding thickness was no longer apparent effect.In brief,You must use organic fertilizer for compact soil which was good structure,simultaneously,using turn-over tillage.