Soil moisture content and surface temperature in tillage systems and stages of development of maize crop

ABSTRACT The tillage systems affect the amount of crop residue on the soil surface, and hence its temperature and moisture content. To evaluate the variation of moisture content and soil temperature in systems of tillage on maize growth stages, an experiment was conducted in Ultisol. The experiment was conducted with randomized complete block with four replications in Petrolina – PE, Brazil. The treatments consisted of five tillage systems applied to the plots – unprepared primary, off-set disc harrow of 0.56 m, off-set disc harrow of 0.61 m, chisel plow and moldboard plow. The soil moisture and temperature readings were taken at 6, 9, 12, 15 and 18 h for the different maize stages V3, V8, R3 and R6. Soil moisture was measured in the layer between 0.00-0.05 m by means of deformed samples by using gravimetric method and soil temperature at the surface with infrared thermometer. Systems of soil tillage and hours of reading influenced the moisture and soil temperature. The highest values of soil moisture content occur in the morning, while the highest temperature of the soil in the afternoon.

摘要
耕作制度可影响土壤表面作物残体的保有量，进而调控土壤温度与含水率。为明确不同耕作制度下玉米各生育期的土壤含水率与温度变化规律，研究团队在巴西佩托利纳（PE）的老成土（Ultisol）中开展田间试验。试验采用随机完全区组设计，设置4次重复，试验地点为巴西佩托利纳-PE地区。试验共设置5种耕作处理：未初级整地、0.56米偏置圆盘耙、0.61米偏置圆盘耙、凿式犁及铧式犁。分别在玉米V3、V8、R3、R6四个生育期，于每日6、9、12、15、18时采集土壤数据。其中，0.00~0.05m土层的土壤含水率采用称重法（gravimetric method）通过扰动土样测定，地表土壤温度则通过红外测温仪（infrared thermometer）测定。分析结果表明，耕作制度与测定时段均会显著影响土壤含水率与温度。土壤含水率峰值出现在清晨时段，而土壤温度峰值则出现在午后时段。