不同控光与灌水量对滴灌玉米田间土壤温度变化规律的影响

为了说明不同控光和灌水量条件下,大田滴灌玉米土壤温度的变化规律,设置两因素的大田小区试验,采用控光率为0%、20%、50%和70%(L1、L2、L3、L4)的遮阴处理,灌水量为3000、3750、4500和5250m^3/hm^2(W1、W2、W3、W4)4个处理进行分析研究。结果表明:不同灌水量处理之间温差显著(P<0.05),W1L1、W2L1、W3L1、W4L1处理0~60cm深土壤平均温差为0.6℃左右,0~30cm深土壤温度对气温响应明显,10cm深处土壤温度日变幅最大,最大可达4.8℃左右;不同控光处理较正常光照处理土壤温度明显下降,W2L2、W2L3、W2L4处理比W2L1处理0~60cm深土壤平均温度下降1.8~2.9℃,W2L2、W2L3、W2L4处理之间0~60cm深平均温差0.6℃左右;W2L2、W2L3、W2L4处理10cm深处日变幅相对W2L1处理较小,对气温的响应程度也明显减小,20~30cm深处土壤温度日变化较平缓;不同控光和灌水量各处理在45~60cm深处土壤温度对气温响应不显著,基本趋于稳定。控光和灌水对土壤温度均有滞后效应,随着土壤深度的增加土壤温度也有滞后效应,不同灌水量下每10cm深滞后2h左右,不同控光条件下每10cm滞后约1h。研究控光和灌水对膜下滴灌玉米大田土壤温度的影响,为研究光、热和水对膜下滴灌玉米的协同调控提供理论依据,对科学种植玉米和指导生产实践具有重要意义。

微咸水膜下滴灌对土壤水盐分布及加工番茄产量的影响

为探明微咸水膜下滴灌对土壤水盐分布及加工番茄生长和产量的影响,通过大田小区试验,设置灌水矿化度和灌水定额两个因素,其中3个灌溉水矿化度水平分别为S1:1 g·L^-1、S2:3 g·L^-1和S3:5 g·L^-1,3个灌水定额分别为W1:305 m^3·hm^-2、W2:458 m^3·hm^-2和W3:611 m^3·hm^-2,来进一步寻求适宜本地区加工番茄生长的微咸水膜下滴灌灌溉制度。结果表明:覆膜微咸水滴灌条件下土壤含水量垂直方向的变化趋势表现为0~20 cm土层随深度增加含水量逐渐降低、20~100 cm土层随深度增加含水量逐渐增大、60~100 cm范围内土层剖面含水量最大的分布规律;土壤含盐量随着灌水矿化度的增大而增加,且随着灌水量的增加土壤盐分逐渐向水平距滴灌带35 cm处聚集。灌水矿化度超过3 g·L^-1时加工番茄株高、茎粗均受到一定程度的抑制作用,但对产量影响不大。本文通过试验得出:灌水定额为611 m^3·hm^-2、矿化度为1 g·L^-1处理为本地区最佳微咸水膜下滴灌处理,加工番茄生长健壮且产量最高,达到127613.2 kg·hm^-2;同时认为,在我国淡水资源比较缺乏的新疆地区可以考虑采用灌水定额458 m^3·hm^-2和灌水矿化度3~5 g·L^-1的微咸水对盐分中等敏感的加工番茄进行灌溉。

Effects of biodegradable mulch on soil water and heat conditions,yield and quality of processing tomatoes by drip irrigation

To combat the problem of residual film pollution and ensure the sustainable development of agriculture in oasis areas,a field experiment was carried out in 2019 at the Wuyi Farm Corps Irrigation Center Test Station in Urumqi,Northwest China.Four types of biodegradable mulches,traditional plastic mulchs and a control group(bare land;referred to as CK)were compared,including a total of six different treatments.Effects of mulching on soil water and heat conditions as well as the yield and quality of processing tomatoes under drip irrigation were examined.In addition,a comparative analysis of economic benefits of biodegradable mulches was performed.Principal component analysis and gray correlation analysis were used to evaluate suitable mulching varieties for planting processing tomatoes under drip irrigation.Our results show that,compared with CK,biodegradable mulches and traditional plastic mulch have a similar effect on retaining soil moisture at the seedling stage but significantly increase soil moisture by 0.5%-1.5%and 1.5%-3.0%in the middle and late growth periods(P<0.050),respectively.The difference in the thermal insulation effect between biodegradable mulch and plastic mulch gradually reduces as the crop grows.Compared with plastic mulch,the average soil temperature at 5-20 cm depth under biodegradable mulches is significantly lowered by 2.04°C-3.52°C and 0.52°C-0.88°C(P<0.050)at the seedling stage and the full growth period,respectively,and the water use efficiency,average fruit yield,and production-investment ratio under biodegradable mulches were reduced by 0.89%-6.63%,3.39%-8.69%,and 0.51%-6.33%(P<0.050),respectively.The comprehensive evaluation analysis suggests that the black oxidized biological double-degradation ecological mulch made from eco-benign plastic is the optimal film type under the study condition.Therefore,from the perspective of sustainable development,biodegradable mulch is a competitive alternative to plastic mulch for large-scale tomato production under drip irrigation in the oasis.