基于2012-2013年陕西省榆林市榆阳区小纪汗乡玉米大田试验结果,利用不同复配比例的砒砂岩改良风沙土(砒砂岩与风沙土按体积比1∶1(T1)、1∶2(T2)、1∶5(T3)混合)处理下土壤水分、地上部生物量、叶面积指数和产量数据对RZWQM2(Root zone water quality model 2)模型进行校正和验证,然后利用验证后的模型模拟不同复配比的土壤水分动态和玉米产量变化。模型校正和验证结果表明,土壤分层含水量模拟值和实测值之间的均方根误差(RMSE)分别在0.011~0.042cm~3/cm~3和0.008~0.029cm~3/cm~3范围内变化;地上生物量模拟值和实测值之间的RMSE分别在512~1245kg/hm~2和598~1461kg/hm~2之间变化;作物产量的模拟值与观测值之间的RMSE变化范围分别为84~249kg/hm~2和71~485kg/hm~2。模型模拟结果表明,RZWQM2模型能够较好地模拟砒砂岩改良风沙土对作物产量的影响,3种砒砂岩改良风沙土配比中,砒砂岩与风沙土的体积比为1∶2处理(T2)下玉米产量最高,1990-2013年的平均产量为3527kg/hm~2,变化范围为880~7206kg/hm~2。因此,砒砂岩与风沙土的体积比为1∶2复配模式下对玉米增产的效果较优,该复配模式可作为该地区砒砂岩改良风沙土复配比例的推荐选择。
英文摘要:
Serious desertification caused by human activity and climate change,in addition to water loss and soil erosion related to Pisha sandstone in the Mu Us sandy land,lead to severe scarcity of soil and water resources,which causes worse local agricultural conditions accordingly.Many physical properties of Pisha sandstone is complementary with that of sand,Pisha sandstone is therefore supposed to be blended to enhance water productivity and arability of sandy land.The root zone water quality model 2(RZWQM2) was calibrated and validated based on 2-year experimental data for composite soils prepared at three ratios of Pisha sandstone to sand(1∶1,1∶2 and 1∶5),and then used to estimate potential yield(Yp) and rainfed potential yield(Yp(r)),along with yield gap(YG(r)) of corn(Zea mays L.) by using the weather data from 1990 to 2013 in Mu Us sandy land.The mean simulated Yp(r) of corn in the compound soil at a ratio of 1∶2(Pisha sandstone:sand) was significantly higher than that of the compound soil at 1∶1 and 1∶5 ratios,respectively.There was no difference in the simulated Yp(r) between those of the 1∶1 and 1∶5 ratios of Pisha sandstone to sand.The mean simulated Yp(r) of corn was 2551kg/hm~2,3527kg/hm~2 and 2924kg/hm~2 and the YG(r) was 6071kg/hm~2,5096kg/hm~2 and 5698kg/hm~2 at 1∶1,1∶2 and 1∶5 ratios,respectively.The results showed the potential of Pisha sandstone as amendment on improving corn yield in Mu Us sandy land.Further research into the long-term effect of Pisha sandstone on soil chemical,biological properties and soil microbial community structure is required to gain a better understanding of the mechanism of Pisha sandstone as amendment for increasing crop yield in Mu Us sandy land,China.