秦王川灌区种植春小麦与披碱草对耕地风蚀的影响差异

Effects of Planting Wheat and Elymus Nutans on Soil Erosion in Qinwangchuan Irrigated Regions

为探寻防治秦王川灌区耕地风蚀危害的可行措施,以春小麦和披碱草及其下方土壤为研究对象,通过测定植物(或根茬)的盖度、高度和地表生物量及耕地地表的粗糙度、湿度、土壤含水量和细颗粒物损失量,比较了不同处理下耕地土壤受风蚀危害的差异。试验结果表明:种植披碱草的地表植被盖度、高度和地表生物量均显著大于种植小麦地(P<0.05);而地表粗糙度、湿度和土壤含水量在各处理间的大小顺序均为:披碱草地>小麦地>裸地;在风蚀期间,耕地受到的风蚀均表现为:秋末冬初风蚀较大,冬季减弱,春季又明显加重的"U"形曲线模式,在此期间的3~5月份风蚀最严重,但秋末的风蚀危害也不容忽视;在风蚀最严重的春季,小麦地与裸地的地表细颗粒物损失量相近;而种植披碱草可显著降低耕地风蚀危害、降幅可达43%。

In order to explore feasible measures for preventing and controlling wind erosion in farmland of Qinwangchuan irrigation regions, the experiment took Triticum aestivum, Elymus nutans and the soil below them as the research objects tocompare the difference of farmland soil wind erosion hazards under different treatments by measuring vegetation （or crop stubble） coverage, height and biomass and cultivated land surface roughness, surface humidity, moisture content and fine particle loss. Results showed that the vegetation coverage, height and above ground biomass of Elymus nutans were significantly higher than those of wheat （P 〈 0.05）. The order of surface roughness, humidity and soil moisture content of different treatments were： grass land〉wheat land〉bare land. In the whole wind erosion season, the wind erosion of farmland was shown as a ＂u--shaped＂ curve pattern that was large in late autumn and early winter, small in winter and significantly enhanced in spring. Among them, the wind erosion from March to May was the most serious, but the wind erosion in October was not negligible. The loss of fine particles in wheat land was similar than that of bare land, when the wind erosion was the most severe during March to May. Planting Elymus nutans could significantly reduce the risk of wind erosion declining rates up to 43%.