不同给水负压对辣椒生长及水分利用效率的影响

为筛选出南方地区辣椒(Capsicum annuumL.)生长最适宜的灌溉负压值,采用土壤盆栽试验的方法,选择2种典型菜园土壤(潮菜园土和红菜园土),研究3个给水负压(-5.0 kPa、-10.0 kPa和-15.0 kPa)对土壤水分含量、辣椒产量、累积耗水量和水分利用效率的影响,探讨负压灌溉下适宜辣椒生长发育的给水水平。结果表明,-5.0 kPa给水负压条件下,潮菜园土和红菜园土的相对含水量分别为61.6%和60.5%;辣椒产量潮菜园土256.0 g/pot,红菜园土141.7 g/pot,显著高于-10.0 kPa和-15.0 kPa处理。辣椒生长期(5月4日—7月21日)-5.0 kPa处理潮菜园土累积耗水量为21.5 dm3,显著大于-15.0 kPa处理,红菜园土为17.6 dm3,显著大于-10.0 kPa和-15.0 kPa处理;水分利用效率潮菜园土2.14 g/kg,红菜园土1.69 g/kg,显著高于-15.0 kPa处理。辣椒各生育期耗水强度,潮菜园土以开花座果期最大,-5.0 kPa处理为0.403 dm3/d,显著大于-15.0 kPa处理,红菜园土以结果期最大,-5.0 kPa处理为0.335 dm3/d,显著大于-10.0 kPa和-15.0 kPa处理。辣椒果长、果径和单果重,红菜园土以-5.0 kPa处理最优,潮菜园土以-10.0 kPa处理最优。综合辣椒产量和水分利用效率,潮菜园土和红菜园土以-5.0 kPa负压灌溉较为适宜。

Effects of different negative pressures on the growth and water use efficiency of pepper plants

In order to select a suitable negative pressure for the growth of pepper (Capsicum annuum L.) in south of China, two vegetable soils (alluvial soil and red soil) were collected and a pot experiment was conducted to investigate the effects of three levels of negative pressure (-5.0 kPa, -10.0 kPa and -15.0 kPa) on soil moisture, pepper yield, total water consumption and water use efficiency. The results showed that under the negative pressure condition of -5.0 kPa, the relative soil water content was 61.6% and 60.5%, the pepper yield was 256.0 g/pot and 141.7 g/pot in alluvial and red soil, respectively, which were significantly higher than those under -10.0 kPa and -15.0 kPa treatments. During the growth stage of pepper from May 4 to July 21, the total water consumption in alluvial soil was 21.5 dm3 under -5.0 kPa treatment, higher than that under -15.0 kPa treatment; while the value in red soil was 17.6 dm3 under -5.0 kPa and was greater than those under both -10.0 kPa and -15.0 kPa. The water use efficiency of pepper under -5.0 kPa treatment was 2.14 g/kg in alluvial soil and 1.69 g/kg in red soil, which were both higher than those under -15 kPa treatment. The water consumption intensity of pepper in alluvial soil was high at the blooming and fruit-setting stage, with a higher value of 0.403 dm3/d under -5.0 kPa than under -15.0 kPa treatment. As for red soil, the water consumption intensity was high at the fruiting stage, also with a higher value of 0.335 dm3/d under -5.0 kPa than under -10.0 kPa and -15.0 kPa treatments. The fruit length, diameter and single weight of pepper in red soil were the optimal under -5.0 kPa treatment, while in alluvial soil they were the best under -10.0 kPa treatment. In terms of pepper yield and water use efficiency, the irrigation level of -5.0 kPa is suitable for pepper in the two selected soils.