不同灌溉方式对秋播甜玉米冠层温光特性及农艺性状的影响

Effect of Irrigation Methods on Canopy Temperature,Photosynthesis and Agronomic Traits of Autumn Sweet Corn

对闽南旱地3种不同灌溉方式对秋播甜玉米田间群体温湿变化及光分布规律进行研究。结果表明:(1)孕穗扬花期的日温变化峰值分别是:喷灌33.1℃、滴灌33.2℃、漫灌35.6℃,喷灌和滴灌比漫灌分别低2.5℃和2.4℃,温度峰值低,变幅小,有利于甜玉米的光合作用和生物合成;相对湿度日变化峰值分别是:滴灌50.1%、喷灌52.0%、漫灌49.6%,滴灌和喷灌分别比漫灌高0.5和2.4个百分点,日平均是滴灌44.9%、喷灌45.6%、漫灌43.0%,滴灌和喷灌比漫灌分别高1.9和2.6个百分点,相对湿度提高增强了甜玉米生长高峰期的水分需求及抗旱能力;光截获率日变化峰值是滴灌55.7%、喷灌54.6%、漫灌52.8%,滴灌和喷灌比漫灌分别高2.9和1.8个百分点,日平均是滴灌34.9%、喷灌34.1%、漫灌32.3%,滴灌和喷灌分别比漫灌高2.6和1.8个百分点,光温效应得到改善;(2)全生育期平均温度分别是滴灌24.1℃,喷灌23.8℃和漫灌24.4℃,滴灌和喷灌所处的温度范围更有利于甜玉米授粉灌浆和干物质同化;全生育期平均相对湿度分别是滴灌48.3%、喷灌49.4%、漫灌46.4%,滴灌和喷灌相对湿度较有利于甜玉米的水分代谢和生长发育;全生育期平均光截获率是滴灌39.6%、喷灌40.2%、漫灌36.2%。滴灌和喷灌改善了光分布条件;(3)滴灌和喷灌均能取得显著增产,滴灌对甜玉米的株高、穗长、穗重和根重影响较大,而喷灌对甜玉米的成穗率、秃尖长和绿叶数改善最为明显。

Effects of drip,sprinkler,and flooding irrigation methods on the temperature,humidity,and sunlight exposure on the fields of autumn sweet corn were studied in southern Fujian.The results showed：（1）At booting and flowering stages of the plants,the peak temperatures in the field with the drip and the sprinkler irrigation were2.4oC and 2.5o C,respectively,lower than the flooding method.The slight differentiations did not alter the photosynthesis and biosynthesis of the sweet corn.The peak RHs with the drip and the sprinkler irrigation were 0.5and 2.4percentage points,respectively,higher than the flooding method,while the average daily RHs were 1.9and2.6percentage points,respectively,higher than the flooding method.The greater RH provided by the two former methods supplied extra moisture and offered drought prevention for the plants.The peak sunlight exposure with the drip and the sprinkler irrigation were 2.9and 1.8percentage points,respectively,while the average daily sunlight exposure was 2.6and 1.8percentage points,respectively,more than the flooding method.Thus,the drip and the sprinkler irrigation increased the sunlight utilization of the plants.（2）In the entire growing stage of the plants,the average surrounding air temperatures with the drip,sprinkler,and flooding irrigation were 24.1℃,23.8℃,and24.4℃,respectively.The temperature range resulted from the drip and the sprinkler irrigation was more conducive to the pollination grouting and dry matter assimilation of the sweet corns.The average RHs with the drip,sprinkler,and flooding irrigation were 48.3%,49.4%,and 46.4%,respectively.The higher RH induced by the drip or sprinkler irrigation benefited the development,water metabolism,and growth of the corn plants.The average sunlight exposure rates with the drip,sprinkler,and flooding irrigation were 39.6%,40.2%,and 36.2%,respectively.Hence,the two former methods of irrigation provided a greater photosynthesis for the plants.And,（3）The yield of the sweet corns grown under the drip or sprinkler irrigation was significantly higher than that of the flooding method.There were significant effects observed of the drip irrigation on the plant height,ear length,ear weight,and root weight of the plants,and those of the sprinkler irrigation on the spike rate,bald tip length,and green leaf count of the sweet corn.