东北黑土区覆膜滴灌下田间微气候和作物生长特征

Study of Field Microclimate and Crop Growth Characteristics with Mulched Drip Irrigation in Black Soil Region of Northeast China

为探讨东北黑土区滴灌种植作物光热水资源利用率和节水增产内在机理,设置覆膜滴灌和未覆膜滴灌2个处理,研究了东北黑土区覆膜滴灌条件下田间微气候和作物生长特征。结果表明,薄膜覆盖可增加近地层的土壤温度和空气温度,降低空气湿度,覆盖处理在0—25cm土层的土壤温度明显高于未覆膜处理,日均地温最大可高5.33℃;覆膜处理的空气温度比未覆膜最大可高0.34℃,相对湿度比未覆膜最低可低2.35%。与未覆膜处理相比,覆膜处理的垄上(滴灌带正下方)和垄边缘土壤蒸发量分别减少52.89,54.16mm,减小幅度分别为46.26%,49.06%。覆膜具有明显的保墒作用,覆膜处理0—50cm土层的平均土壤含水率大于未覆膜处理,最大增幅达46.65%。覆膜处理对LAI、株高、干物质均有一定的有益影响;在施肥量为330kg/hm^2的条件下,覆膜对玉米的增产效果不明显;但增加了玉米粒的氮素含量,提高了粗蛋白含量,玉米粒的氮素含量比未覆膜高8.45%,其粗蛋白含量高8.45%。

For better understanding the internal mechanism of mulched drip irrigation on water-heat resource utilization in field and maize yield in black soil region, field experiments were carried out in 2014 in Heilongjiang province, China. 2 treatments were set up in the experiment, including mulched drip irrigation treatment, and non-mulched drip irrigation treatment. The characteristics of field microclimate and crop growth were studied in this paper. The results showed that the mulched drip irrigation could increase soil temperature, air temperature and reduce air humidity in the near ground layer. The mulched drip irrigation significantly increased the temperature of 0-25 cm soil layer, and at 5-25 cm soil depth, the daily temperature of 5-25 cm soil layer could be increased by 5.33 ℃ at most, compared with that of the non-mulched treatment. Furthermore, the daily air temperature for the mulched drip irrigation treatment was 0.34 ℃ higher and the relative humidity was 2.35% lower than those for the non-mulched drip irrigation treatment. Compared with the non-mulched drip irrigation treatment, the mulched drip irrigation reduced soil evaporation volume on ridge （directly below the drip tape） and ridge edge by 46. 26% and 49.06%, respectively. Film mulching had an obvious effect on keeping water. The mulched drip irrigation treatment increased the soil moisture content of 0-50 cm soil layer by 46. 65% at most. For crop growth, the growth speed of LAI, plant height, and aboveground dry matter for the mulched drip irrigation treatment were greater than those for the non-mulched drip irrigation treatment during the early growing stage. Compared with that of the non-mulched treatments, the increase of the average grain yield for the mulched drip irrigation treatment increased the content of the nitrogen uptake and treatment was not obvious. The mulched drip irrigation crude protein were 8.45%.