不同配方土壤熟化调理剂对新修梯田土壤改良效果的影响

针对西北黄土高原半干旱区新修梯田土壤瘠薄、保水保肥能力差的特点,通过3年的田间定位试验,在氮磷肥平衡施用基础上,研究添施不同配方土壤熟化剂对新修梯田土壤理化性状、养分状况与作物产量等方面的影响。结果表明:(1)施用不同配方土壤熟化剂可降低新修梯田土壤容重,增大毛管孔隙度和田间持水量,增加土壤有机质、全氮、速效磷和速效钾含量;且表层(0~10 cm)熟化效果好于底层(10~20 cm)。与试验前相比,表层土壤容重降低5.14%~18.49%,孔隙度和田间持水量分别增加9.14%~18.86%和10.96%~17.19%;土壤有机质、全氮、速效磷和速效钾分别增加56.11%~114.19%、9.84%~78.69%、48.52%~268.50%、70.10%~427.53%;(2)与CK相比,A处理的培肥效果最显著,容重年均降低0.06 g·cm-3,孔隙度和田间持水量年均分别增加3.15、0.45%;土壤有机质、全氮、速效磷和速效钾的年增加速率分别提高2.48 g·kg~(-1)、0.2 g·kg~(-1)、7.82mg·kg~(-1)、129.23 mg·kg~(-1);其余培肥处理的效果为BC、D、ECK;(3)施用土壤熟化剂提高了作物产量和水分利用效率,以A配方的效果最好,2012、2013年马铃薯产量较CK分别提高37.69%、50.93%,2014年小麦产量较CK提高94.41%;3年A配方的水分利用效率较CK分别提高43.09%、48.71%、102.31%,且差异显著。综合可知,A配方(黑矾、腐植酸、氯化钾、微肥、DA-6用量分别为375、600、150、45、150×10-3kg·hm-2)对于改善土壤理化性状、提高土壤养分、水分利用效率和作物增产效应最佳,为西北黄土高原半干旱区新修梯田快速培肥较适宜的措施。

Effect of different formula of modifiers on soil improvement of newly built terrace

To study the effect of different formula of modifiers on soil physical and chemical properties ,nutrient sta-tus of the new terrace and the yield of the crops ,a 3-year field experimental trial was carried out .The results showed that application of different modifiers formula reduced soil bulk density ,increased soil porosity and field water capacity , increased soil organic matter ,total nitrogen ,available phosphorus and available potassium content .The effect of the sur-face layer (0 to 10 cm ) was better than that of the bottom layer (10 cm to 20 cm ) .The soil bulk density of the surface layer was decreased by 5 .14% ~18 .49% , soil porosity and field capacity by 9 .14% ~18 .86% and 10 .96% ~17 .19% ,respectively .Soil organic matter ,total nitrogen ,available phosphorus and available potassium were increased by 56 .11% ~114 .19% ,9 .84% ~78 .69% ,48 .52% ~268 .50% ,70 .10% ~427 .53% respectively . (2 ) Com-pared with CK ,the effect of A treatment was the largest ,with an average annual decrease in the soil bulk density of 0 .06 g·cm-3 ,an average annual increase in soil porosity and field capacity of 3 .15% and 0 .45% .And the average annual increase rate of soil organic matter ,total nitrogen ,available phosphorus and available potassium were 2 .48 g·kg-1 ,0 .2 g·kg-1 ,7 .82 mg·kg-1 ,129 .23 mg·kg-1 ,respectively .The effects of other treatments showed an order of B>C ,D ,E>CK .(3) The application of modifiers could improve the crop yield and water use efficiency .Take A formula as an example ,the potato yield was increased by 37 .69% and 50 .93% in 2012 and 2013 ,respectively ,and wheat production by 94 .41% in 2014 compared with CK .The water use efficiency of A treatment significantly was increased by 43 .09% , 48 .71% and 48 .71% in the year of 2012 ,2013 and 2014 ,respectively .Taken together ,we proposed a formula for new terrace on semiarid region of the Loess Plateau .