周勋波，学者全讯担保网主页-全讯担保网

management practices can have a major impact on the successful production of winter cereals. a field experiment was conducted with winter wheat (triticum aestivum) to compare the effects of two row spacing planting patterns (row width set at 30 cm, 30; or row widths set at a narrow row of 20 cm and a wide row of 40 cm, 20 40) and four irrigation schedules (no irrigation, t0; irrigation given at stem elongation stage, t1; at stem elongation and heading stage, t2; at stem elongation, heading and milk stage, t3) on yield, water use efficiency (wue), evapotranspiration (et) and soil water content (swc) for the 2003/2004 and 2004/2005 seasons at taian, shandong province, china. mean soil daily evaporation (es) was greater in the wide row than the narrow row, and resulted in decreased swc in the wide row. for the same irrigation treatment, no significant differences in changes of swc and yield were found between the row-spacing planting patterns in either season. differences in et were found in 2005 with et from the t0 treatment being much lower than the irrigated treatments for both planting patterns. during the cropping season in 2005, wue of the t3 treatment was lower than from the t1 and t0 treatments at the same planting patterns. the wue of the 20 40 planting pattern was lower than that of the 30 planting pattern with the same irrigation schedule, perhaps due to elevated levels of evaporation from the soil beneath the canopy and decreased yields for the 20 40 planting pattern. therefore, based on wue, the effect of the 30 planting pattern was better than that of the 20 40.

productivity and water resource-use efficiency are crucial issues in sustainable agriculture, especially in high-demand water resource crops such as soybean [glycine max (l.) merr.]. the aims of this research were to compare planting pattern in soybean, evaluating soil moisture content (smc), yield and water use efficiency (wue). a 2-year field experiment (2006-2007) was carried out in the north of china. the summer soybean (cv. ludou 4) experiment consisted of 5 planting patterns under the same plant population density (3.09×105 plant/ha), and row spacing (cm)×plant spacing (cm) was 18×18 cm (a), 27×12 cm (b), 36×9 cm (c), 45×7.2 cm (d), 54×6 cm (e). the results showed that smc and soil storage water (ssw) decreased with evapotranspiration (eta) increments after reproductive growth stage, and there were remarkable differences between treatments with decreasing rainfall. smc curve characteristics in the 0–90 cm soil profile were related to rain; the scope changes of shallow smc were higher than those of deep smc. the study revealed that yield and wue had a negative correlation with row spacing, and they were statistically greater in narrow rows, which approximated equidistant plant spacings, compared to wider rows (p < 0.05). the study also indicates that enhanced productivity and wue of rainfed summer soybean can be achieved via row spacing reduction and plant spacing widening under uniform planting density.