共查询到19条相似文献，搜索用时 265 毫秒
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通过田间实验,研究亚铵法制浆中段水经土地处理的同时作为灌溉用水的农田养分平衡状况及经济效益。结果表明,亚铵法制浆中段水灌溉条件下,冬小麦-水稻轮作体系各废水处理氮、磷、钾均处于盈余状态,在最佳组合体系下氮、磷、钾盈余分别达到5.21%、60.10%、37.36%。小麦季推荐施肥量氮肥(按纯氮计)286.8 kg/hm2,磷肥(按P2O5计)64.2 kg/hm2,不施钾肥;水稻季氮、磷、钾肥均不施。亚铵法制浆中段水灌溉,1年每公顷土地可以处理废水19200 m3,产生经济效益41842元。由于小麦季废水灌溉量较少,因此可以通过湿地处理法来解决此时中段水过量的问题。 相似文献
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木质素复混肥对土壤脲酶活性的影响 总被引：4，自引：0，他引：4
通过盆栽试验,研究以亚铵法制浆废液氨解产物为原料研制的复混肥对土壤脲酶活性的影响,以确定其对肥料缓释性能的影响.试验结果表明,以亚铵法制浆废液氨解产物为原料研制的复混肥,能够抑制土壤脲酶活性,降低氮素的释放速度,从而提高肥料的利用率,旨在以亚铵法制浆废液氨解产物研制缓释混肥提供理论依据. 相似文献
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新型木质素缓释肥料氮磷利用率研究 总被引：7，自引：0，他引：7
通过对亚铵法制浆废液氨解产物为原料研制的复混肥进行盆栽试验,探索其对肥料中氮、磷利用率的影响,为亚铵法制浆废液的资源化利用提供一理想途径。盆栽试验结果表明,以亚铵法制浆废液氨解产物为原料研制的复混肥,具有缓释作用,能够抑制肥料中氮的释放速度,提高氮的利用率;并能增强磷在土壤中的溶解,促进磷的活化,提高磷的利用率。 相似文献
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再生水灌溉对土壤盐分和重金属累积分布影响的研究 总被引：12，自引：1，他引：11
再生水是农业灌溉的重要水资源。为了合理利用城市污水处理后的再生水资源,采用天津市纪庄子污水处理厂二级出水作为再生水,以自来水为对照进行叶类蔬菜小区种植试验,研究了再生水灌溉对菜地土壤次生盐渍化及盐分离子和重金属离子累积分布规律的影响。结果表明:除0~15 cm土层全盐量增加外,15~45 cm土壤层盐分累积现象与自来水灌溉相比无明显差异。与自来水灌溉相比,短期内采用再生水灌溉不会显著增加土壤阳离子含量。重金属在土壤中的累积也不明显,同时,不同再生水灌溉水量条件下,土壤中重金属含量无显著差异,且土壤中的重金属含量都远低于国家标准规定的允许值,表明再生水短期灌溉对土壤环境不会造成污染影响。 相似文献
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通过肥料的沙柱淋溶性试验,研究了以亚铵法制浆蒸煮废液氨解产物为原料研制的木质素肥料的缓释特性。试验结果表明,利用亚铵法制浆蒸煮废液氨解产物研制的复合肥具有较低的溶出率,能延缓氮素的释放速度,并且呈现出随着氨解产物用量的增加肥料抗淋溶能力增强的趋势。因此,亚铵法制浆蒸煮废液氨解产物可用于研制缓释肥料。 相似文献
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新疆玛纳斯河流域灌溉水质对滴灌农田土壤盐分影响研究 总被引：1，自引：0，他引：1
通过测定玛纳斯河流域灌溉水矿化度,盐分离子含量以及灌区膜下滴灌棉田土壤盐分离子类型,研究灌溉水质对膜下滴灌农田土壤盐分积累的影响。结果表明流域灌溉用水均为弱矿化水,其中渠水矿化度低于井水。灌溉后,农田土壤中除HCO3-积累外,其余盐分离子含量均降低,且井水灌溉农田土壤HCO3-积累量,总盐含量均大于渠水灌溉农田,灌后灌区土壤主要盐分变为Na2SO4,盐分毒害作用降低。因此,玛纳斯河流域渠水更适于灌溉,其洗盐效果更佳,井水灌溉农田可能发生土壤碱化。 相似文献
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长期咸水灌溉对小麦光合特性与土壤盐分的影响 总被引：6，自引：0，他引：6
于2013—2015年研究了不同咸水利用方式(CK,淡水;T1,咸水与淡水混配为1.8 g/L的混合水灌溉;T2,3.6 g/L咸水与淡水交替灌溉;T3,3.6 g/L咸水灌溉;T4,无灌溉)对冬小麦光合特征及土壤盐分的影响。结果表明:T3和T4处理的株高、叶面积指数、叶面积持续期、叶绿素含量、最大净光合速率(Pnmax)、表观光量子效率(φ)、暗呼吸速率(Rd)和产量较淡水处理显著下降,且连续灌溉3.6 g/L的咸水导致土壤发生积盐,不宜连续灌溉。T1和T2处理与CK的株高、光合特性无显著差异,土壤盐分虽有一定积累,但未影响作物的生长。可见,T1(咸淡混溉)和T2(咸淡水交替灌溉)处理的咸水利用方式对冬小麦生长无负调控效应。从土壤生态环境及小麦产量的影响角度考虑,混灌和轮灌既能保证作物产量较淡水灌溉不减产,土壤未发生次生盐渍化,同时节约淡水资源。 相似文献
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为了探究不同咸淡水交替灌溉对设施番茄土壤盐分胁迫响应及产量品质的影响，以“秦岭蔬越”番茄品种为研究对象，共设置W1 （淡咸咸）、W2 （淡咸淡）和W3 （咸淡淡） 3种咸淡水交替灌溉方式，并以淡水灌溉（CK）对照。结果表明：在咸淡水交替灌溉方式下，番茄生育期土壤盐分出现逐渐累积趋势，整体表现为W1>W2>W3处理，且W1、W2处理土壤盐分表聚现象较为严重，而W3处理土壤盐分有向下淋洗趋势，土壤表层积盐较轻。不同咸淡水交替灌溉后，由于土壤盐分累积程度不同，使番茄受到盐分胁迫的差异较大，其中番茄叶片内丙二醛（MDA）、脯氨酸（PRO）、可溶性蛋白（SP）、可溶性糖（SS）及超氧化物歧化酶（SOD）、过氧化物酶（POD）、过氧化氢酶（CAT）含量均有不同程度增加。由相关性分析可知，土壤盐分与番茄叶片CAT、PRO呈极显著性正相关（P<0.01），与叶片SS呈显著性正相关（P<0.05），说明番茄通过改变各种保护酶活性及渗透物质含量提高自身抗逆性，以应对盐分胁迫危害。通过对比分析，W3处理番茄可溶性固形物、硝酸盐、Vc和总酚含量及产量均高于对照，说明适宜的咸淡水交替灌溉... 相似文献
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基于距离反比法的土壤盐分三维空间插值研究 总被引：1，自引：0，他引：1
以新疆兵团一块面积约70 hm2的盐碱地为研究对象,采用EM38与土钻取样相结合的方法得到了126个点不同土层(0~200 cm)的1 386个土壤盐分数据,应用三维距离反比法(3D-IDW)对土壤盐分进行了空间插值,探讨了垂向坐标扩大倍数和搜索点数对插值结果精度的影响。结果表明,研究区0~140 cm土层盐分平均含量较高,为1.84~2.11 g/kg,盐分变异较大,而140~200 cm土层盐分平均含量较低,为1.74~1.79 g/kg。所有土层盐分含量的统计特征值(平均值、标准差和变异系数等)均随土层加深而呈现递减的趋势。土壤盐分实测值和估计值的均方根误差随垂向坐标扩大倍数的增大而减小,随搜索点数的增加而增大,其值在0.1~0.4 g/kg范围内变化,当垂向坐标扩大300倍、搜索点数为6个时,插值效果较优。采用确定的参数对研究区的土壤盐分进行了三维空间插值,结果表明土壤盐分空间分布特征与实测值比较吻合,大部分区域土壤盐分含量小于2.5 g/kg,靠近北部和南部边界区土壤含盐量较低,属于非盐化土区,而大于4 g/kg盐化土主要分布在中间和南部局部区域。研究区80%土壤为非盐化土和轻度盐化土,20%为中度和重度盐化土。影响该区盐化土分布的主要因素有灌溉、局部地形、粘土层位置、地下水埋深和矿化度。当不同方向的取样间距相差很大时,选取合适的垂向坐标扩大倍数和搜索点数对保障3D-IDW法的插值结果精度至关重要。 相似文献
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为探明微喷灌施肥对三七土壤氮素运移转化影响,2017—2020年在泸西县大栗树村三七种植基地设置3个灌水水平0.4FC(W1),0.6FC(W2),0.8FC(W3),4个施肥水平3.20(F1),4.80(F2),6.20(F3)和120.00 kg/ha(F4),CK为对照,共13个处理.研究微喷灌施肥条件下不同灌水及施肥对三七土壤全氮、硝态氮和铵态氮运移转化影响.结果表明:不同灌水施肥全氮质量比随时间增加先增大后减小,硝态氮质量比随时间增加先减小后增大,铵态氮质量比随时间增加逐渐减小,8月W2F3全氮质量比最大,9月W2F4硝态氮质量比最大,6月W2F4铵态氮质量比最大.全氮和铵态氮质量比随土层深度增加逐渐减小,硝态氮质量比随土层深度增加先减小后增大,全氮、硝态氮和铵态氮聚集在土层0~10 cm,W2F3土壤全氮和硝态氮质量比最大,W2F4铵态氮质量比最大.灌水量与硝态氮和铵态氮相关性具有统计学意义(P<0.01),与全氮呈负相关且相关性具有统计学意义(P<0.05),施肥量与硝态氮呈正相关且相关性具有统计学意义(P<0.01),与铵态氮相关性具有统计学意义(P<0.05).该研究明确灌溉施肥可调控酸性红壤土三七氮素运移转化特性,改善农田微生态环境,提高水氮利用效率,为有效防治病虫害提供技术支持和理论依据. 相似文献
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北方旱作农业区蓄水保墒耕作模式研究 总被引：3，自引：0，他引：3
分析了北方旱作农业的现状,提出了适合东北垄作区的三年轮耕法和西北黄土高原区的自然降水高效利用技术,并对其进行了试验。东北耕法：秸秆还田使土壤含水率提高10%,土壤有机质3年提高0.06个百分点,土壤容积密度降低0.09g/cm^3,深松使0-100cm土层土壤含水率提高26.2%,少耕精播土壤含水率提高3个百分点;西北新耕法：冬小麦蓄水率提高18.5%,水分生产效率提高25.6%;春玉米在0-10cm土层,含水率提高30%,水分生产效率提高47.6%。2年连续秸秆还田试验,有机质质量分数增加0.05%-0.1%,全氮质量比增加0.1g/kg左右。 相似文献
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D. P. Sharma K. V. G. K. Rao K. N. Singh P. S. Kumbhare R. J. Oosterbaan 《Irrigation Science》1994,15(1):25-33
In arid and semi-arid regions, effluent from sub-surface drainage systems is often saline and during the dry season its disposal poses an environmental problem. A field experiment was conducted from 1989 to 1992 using saline drainage water (EC=10.5–15.0 dS/m) together with fresh canal water (EC=0.4 dS/m) for irrigation during the dry winter season. The aim was to find if crop production would still be feasible and soil salinity would not be increased unacceptably by this practice. The experimental crops were a winter crop, wheat, and pearl-millet and sorghum, the rainy season crops, grown on a sandy loam soil. All crops were given a pre-plant irrigation with fresh canal water. Subsequently, the wheat crop was irrigated four times with different sequences of saline drainage water and canal water. The rainy season crops received no further irrigation as they were rainfed. Taking the wheat yield obtained with fresh canal water as the potential value (100%), the mean relative yield of wheat irrigated with only saline drainage water was 74%. Substitution of canal water at first post-plant irrigation and applying thereafter only saline drainage water, increased the yield to 84%. Cyclic irrigations with canal and drainage water in different treatments resulted in yields of 88% to 94% of the potential. Pearl-millet and sorghum yields decreased significantly where 3 or 4 post-plant irrigations were applied with saline drainage water to previous wheat crop, but cyclic irrigations did not cause yield reduction. The high salinity and sodicity of the drainage water increased the soil salinity and sodicity in the soil profile during the winter season, but these hazards were eliminated by the sub-surface drainage system during the ensuing monsoon periods. The results obtained provide a promising option for the use of poor quality drainage water in conjunction with fresh canal water without undue yield reduction and soil degradation. This will save the scarce canal water, reduce the drainage water disposal needs and associated environmental problems. 相似文献
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《Agricultural Water Management》1999,41(1):57-70
The salinity condition in the root zone hinders moisture extraction from soil by plants, because of osmotic potential development in soil water due to presence of salts, which ultimately, decreases transpiration of plants and thereby affects crop yield. Therefore, an effort was made in this study to quantify the impact of salinity on soil water availability to plants. The movement of salts under irrigation and evapotranspiration regimes in root zone of soil profile was studied throughout the growing season of wheat crop with adopting exponential pattern of root water uptake. A model was developed to analyze soil water balance to find out moisture deficit because of salinity. A non-linear relationship was formulated between moisture content and salt concentration for simultaneous prediction. The Crank–Nicolson method of Finite Differencing was used to solve the differential equations of soil water and solute transport. The effect of various salt concentrations on transpiration was analyzed to develop a relationship between relative evapotranspiration and relative yield. Relationships among salt concentration, matric potential, moisture deficit and actual transpiration were also established to provide better understanding about impact of salinization and to provide guidelines for obtaining better crop yields in saline soils. 相似文献
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Summary A line-source field experiment was conducted to study the interactive effects of four levels of soil salinity, five rates of applied nitrogen fertilizer and six levels of irrigation on the production of field corn (Zea mays L.). In general, increased levels of soil salinity and decreased irrigation reduced grain and stover (stems and other above-grand dry matter) yields. Increased quantities of irrigation, presumably through maintenance of high (less negative) total soil water potential, were effective in decreasing the effect of salinity, and as a result improved yield. The highest salinity level (9.6 mmho/cm) resulted in dry matter yield reductions of 41 and 93 percent of the maximum observed yield at the highest (479 mm) and lowest (210 mm) irrigation levels respectively, averaged over all fertility levels. Under the same conditions grain yield declined by 48 and 96 percent. Yield was not improved as a result of applying nitrogen. Main effects on yield of salinity (1% level), water (1% level) and nitrogen (5% level) were found. Interactive effects upon yield were demonstrated for salinity X nitrogen (1% level) and salinity X water (1% level) combinations. Nitrogen content of stover and grain rose with increased levels of soil salinity and nitrogen, and declined with increased irrigation. A salinity X nitrogen interaction effect was demonstrated for nitrogen content of the grain, and a salinity X water effect demonstrated for stover. Multiple regression equations for stover and grain yields as functions of salinity, fertility and irrigation were developed (R
2 = 0.88 and 0.85 respectively).Utah Agricultural Experiment Station Journal Paper No. 2331Present address of the senior author: FAO, Addis Abeba, Ethiopia 相似文献
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种植结构与土壤盐分的协同程度与发展关系关乎灌区水土生态质量与农业可持续发展,联动灌区种植结构提取与土壤盐分空间分析对于灌区生态环境评价与治理、保障耕地和粮食安全等具有重要意义。本文以内蒙古河套灌区永济灌域为研究区,利用2021—2022年生育期Landsat 8 OLI遥感数据与地面种植结构调查数据,分别构建决策树、支持向量机、随机森林分类模型,通过对比分析遴选出灌域适用的最优模型,准确获取灌域种植结构分布结果,同时进一步结合灌域土壤盐分实测数据及其空间异质特征,对种植结构与土壤盐分的协同关系进行深入探讨与分析。结果表明,3种模型的分类精度由大到小为随机森林、决策树、支持向量机,2021、2022年随机森林分类模型的总体精度、Kappa系数分别为92.81%、0.91,91.64%、0.89,为3种模型中精度最高,故选定随机森林模型作为最优模型;灌域内土壤盐分呈现“北部重,中、南部轻”的空间分布特征,2021、2022年土壤盐分的半方差函数适用于Gaussian模型,土壤盐分空间自相关在“中—强”等级变化;受土壤盐分制约,葵花以北部地带种植为主,玉米、小麦、小麦套种玉米(套种)和瓜菜等... 相似文献