Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Soil Science submitted time 2023-03-28 Cooperative journals: 《干旱区研究》
Abstract： Four irrigation water salinity levels, namely, 0.85 g·L-1 (CK, local irrigation water salinity), 3 g·L-1 (S1), 5g ·L- 1 (S2), and 8 g ·L- 1 (S3), were examined to explore the effects of different salinity levels on soil respiration rate in cotton fields. A cotton field experiment with drip irrigation under film was carried out in Xinjiang. During the growth period of cotton, soil respiration rate (Rs) was recorded twice a month, along with soil temperature (ST), water content, electrical conductivity (EC), nitrate nitrogen content (NO-3 -N) and ammonium nitrogen content (NH+ 4 -N) . The influence of soil parameters on soil respiration rate under different salinities of irrigation water was studied by path analysis. Results showed that brackish water irrigation (S1 and S2) increased soil moisture content, EC and ammonium nitrogen content to a certain extent. Salt water irrigation (S3) significantly increased soil moisture and salinity, and decreased soil nitrate nitrogen content. The increase in the salinity of irrigation water decreased the soil respiration rate. The correlation between soil moisture and temperature and respiration rate decreased with the increase in the salinity of irrigation water. The quadratic function was used to represent the response of ST in 0-10 cm soil layer to soil respiration rate (R2=0.669, P< 0.001). The optimal ST for soil respiration rate was 26.9 ℃ . Under saline irrigation, the stepped- regression equation containing ST, conductivity, and nitrate nitrogen content could explain 85% of the variation of soil respiration rate. In conclusion, the use of 3 g·L- 1 irrigation water for drip irrigation under film can reduce soil respiration rate and farmland carbon emissions without significantly increasing soil salt content. This work provides theoretical support for the development and utilization of brackish water resources in Xinjiang.
Subjects: Environmental Sciences, Resource Sciences >> Basic Disciplines of Environmental Science and Technology submitted time 2020-06-21 Cooperative journals: 《干旱区研究》
Abstract：为阐明新疆伊犁河南岸灌区不同滴灌应用年限下新开垦耕地土壤水分分布和土壤全氮及有机质分布，进一步了解干旱区荒地引水灌溉开垦过程中土壤养分变化，本文以伊犁河流域连续新开垦地区——伊犁河南岸灌区管理处为研究区，以冬小麦（Triticum aestivum L.）为研究对象，通过监测不同滴灌应用年限（1 a，2 a，3 a，4 a）以及未开垦荒地（CK）0~60 cm剖面土壤水分、全氮含量和土壤有机质含量，揭示滴灌应用年限对滴灌条件下土壤理化性质以及冬小麦产量的影响。结果表明：新垦土地土壤含水率会随滴灌应用年限延长而增加，种植和灌溉会改善新开荒地的土壤水入渗条件，有利于耕作层水分调蓄；新垦土地各层土壤全氮会随滴灌应用年限增加而增加，且随深度增加分布趋势由开垦前先减少后增加变化为先增加后减少，在0~30 cm土层出现表聚现象；不同滴灌应用年限0~60 cm土壤有机质含量随年限增加而增加，开垦种植增加了0~40 cm土壤有机质含量，并在0~20 cm土层明显富集；根据全国第二次土壤普查养分分级相关标准，研究区荒地开垦后土壤养分全氮及有机质均提高了一级；新开垦耕地灌溉1~4 a，冬小麦产量随滴灌应用年限的增加而增加。养分及产量增加的主要原因在于当地现行的灌溉制度及作物秸秆残留。
Subjects: Environmental Sciences, Resource Sciences >> Basic Disciplines of Environmental Science and Technology submitted time 2018-11-08 Cooperative journals: 《干旱区研究》
Abstract：为探寻棉田土壤中残膜污染状况以及覆膜30 a棉田土壤中的残膜分布趋势，对试验区121团覆膜年限分别为5 a，9 a，11 a，13 a，15 a和19 a共6块棉田进行取样研究。运用Matlab程序构建BP神经网络模型，对取样数据进行分层预测和整体预测，结果表明：运用模型对残膜面积和质量数据进行整体预测，能够更好地反映实际情况下残膜在棉田土壤中的分布趋势，能够精准地预测本地区覆膜30 a棉田土壤中地膜残留状况；同时随着覆膜年限的增加，土壤表层大面积残膜在耕地作业下逐年碎裂，并向深层土壤移动，在30～40 cm深度的土壤中逐年残留。通过预测得到覆膜30 a棉田残膜密度达到419.19 kg·hm-2，超出国家标准限值75.0 kg·hm-2近6倍，为解决此问题可以覆盖厚度大于0.010 mm的农用地膜，并提高地膜回收率来保证棉田的可持续发展。
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