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1.
Mulching is one of the important agronomic practices in conserving the soil moisture and modifying the soil physical environment. Wheat, the second most important cereal crop in India, is sensitive to soil moisture stress. Field experiments were conducted during winter seasons of 2004-2005 and 2005-2006 in a sandy loam soil to evaluate the soil and plant water status in wheat under synthetic (transparent and black polyethylene) and organic (rice husk) mulches with limited irrigation and compared with adequate irrigation with no mulch (conventional practices by the farmers). Though all the mulch treatments improved the soil moisture status, rice husk was found to be superior in maintaining optimum soil moisture condition for crop use. The residual soil moisture was also minimum, indicating effective utilization of moisture by the crop under RH. The plant water status, as evaluated by relative water content and leaf water potential were favourable under RH. Specific leaf weight, root length density and dry biomass were also greater in this treatment. Optimum soil and canopy thermal environment of wheat with limited fluctuations were observed under RH, even during dry periods. This produced comparable yield with less water use, enhancing the water use efficiency. Therefore, it may be concluded that under limited irrigation condition, RH mulching will be beneficial for wheat as it is able to maintain better soil and plant water status, leading to higher grain yield and enhanced water use efficiency.  相似文献   

2.
Irrigation management strategy invites the quantification of crop response to irrigation frequencies. Conventionally, mulches increase the yield and water use efficiency (WUE) to a great extent by augmenting the water status in the root zone profile. A field study was carried out during the winter season (November-March) of 2003-2004 and 2004-2005 at the Central Research Farm of Bidhan Chandra Krishi Viswavidyalaya (Latitude 22°58′N, Longitude 88°31′E and altitude 9.75 m amsl), Gayeshpur, India, to evaluate the effect of irrigation frequencies and mulches on evapotranspiration rate from tomato crop field as well as leaf area index (LAI), fruit yield and WUE of the crop. The experiment was laid out in a split-plot design where three irrigation treatments {rainfed (RF); CPE50 and CPE25 where irrigation was given at 50 and 25 mm of cumulative pan evaporation (CPE)} were kept in the main plots and the subplots contained four mulch managements {no mulch (NM), rice straw mulch (RSM), white polyethylene mulch (WPM) and black polyethylene mulch (BPM)}. Under CPE25, tomato crop recorded significantly higher leaf area index (LAI) over CPE50 and rainfed condition. LAI value under BPM was 9-30% more over other mulches. Maximum variation of LAI among different treatments was recorded at 60 days after transplanting (DAT). Fruit yield under CPE25 was 39.4 Mg ha−1; a reduction of 7 and 30% has been obtained under CPE50 and RF condition. The use of mulch increased 23-57% yield in comparison to NM condition. Actual evapotranspiration rate (ETR) was 1.82 mm day−1 under CPE25 and declined by 15 and 31% under CPE50 and RF condition, respectively. The variation of ETR among different mulches became more prominent under maximum water stressed (RF) condition, whereas the variation was negligible under CPE25 frequency. Irrespective of mulching WUE was highest under moderately wet (CPE50) soil environment. Among different mulches, BPM was responsible for attaining the highest WUE value (25.1 kg m−3), which declined by 22, 21 and 39% under WPM, RSM and NM, respectively.  相似文献   

3.
Field trials were conducted during the wet seasons of 1980 and 1981 to find out the response of legumes to mulch induced soil environment in the arid area of western Rajasthan, India. With increasing amounts of grass mulch there was a decrease in maximum soil temperature and an increase in root growth, nodulation, shoot growth and plant water status, particularly during periods of moisture stress. Mulching reduced weed population and weed growth. At 9 t ha?1 of mulch there was an increase of 200% in the average production of green gram (Vigna radiata), dew gram (Phaseolus aconitifolius) and cluster bean (Cyamopsis tetragonoloba). Though there were no significant differences in water use by the crop, water use efficiency was generally higher in mulched plots. Waste grass therefore can be used favourably as mulching material for increasing crop production.  相似文献   

4.
Fresh water shortages are severally restricting sustainable agriculture development in the North China Plain. The scarcity of fresh water has forced farmers to use brackish water from shallow underground sources, which helps to overcome drought and increase crop yields but also increases the risk of soil salinization. To identify safe and effective ways of using brackish water in this region, field experiments were conducted to evaluate the effect of brackish water irrigation and straw mulching on soil salinity and crop yield in a winter wheat-summer maize double cropping system. The experiment was in a split-plot design. Six rates of straw mulching (0, 4.5, 6.0, 7.5, 15.0 and 30.0 Mg/ha) were assigned to the main plots and two irrigation water qualities (i.e. brackish water with salt content of 3.0-5.0 g/L and fresh water with only 1.27 g salt/L) were applied to subplots. The brackish water irrigation significantly increased the salt content at different soil depths in the upper 1 m soil layer during the two growing seasons. Straw mulching affected the vertical distribution of salt in the brackish water irrigation plots and the average salt content of straw mulch treatments (4.5, 6.0, 7.5, 15.0 and 30.0 Mg/ha) within the 0-20, 20-40 and 0-100 cm soil depths was 10.2, 14.0 and 1.8% lower than that without straw mulch (A0). No salt accumulation occurred to a depth of 1 m in the brackish water irrigation plots and there was no correlation between the value of SAS (salt accumulated in 1 m of soil) and straw mulch rate. In 2000 and 2001, the salt content within the 0-40 cm soil layer in brackish water irrigation plots increased due to high evaporation rates during April-June, and then decreased up to September as salts were leached by rain. For the fresh water irrigation plots, the salt content remained relatively stable. Straw mulching affected the salt content in the 0-40 cm soil layer in brackish water irrigation plots in different periods of 2000 and 2001, but no correlation between salt content and straw mulch rates was observed except in September of 2000. Unlike for wheat, the yield of maize increased as the straw mulch rate increased according to the equation, y = 0.1589x + 5.3432 (R2 = 0.6506). Our results would be helpful in adopting brackish water irrigation and straw mulching in ways that enhance crop yields and reduce the risk of soil salinization. However, long-term effects of brackish water irrigation and straw mulching on soil salinity and crop yield need to be further evaluated for sustainability of the system.  相似文献   

5.
以西北旱区河西民勤灌区为研究区,2017年采取田间监测试验与室内机理试验相结合、田间小区控制试验和理论分析相结合的研究方法,对食葵进行不同方式覆盖种植,覆盖方式设有3个水平:无覆盖（CK）、秸秆覆盖（S）和碎麦秸垫膜覆盖（SF）,灌溉定额采用当地农户普遍采用定额900 m3/hm2,观测分析不同覆盖方式下0～120 cm土壤含水量、土壤温度和食葵产量,从而选择最优覆盖方式。试验结果表明:整个生育期内土壤贮水量在不同覆盖方式下均表现为SF＞S＞CK,秸秆覆盖（S）、碎麦秸垫膜覆盖（SF）较无覆盖（CK）提高了2.1%和12.9%;观测6个土层（0、5、10、15、20和25 cm）地温,不同覆盖方式下地温均随土层深度增加而下降,S和SF处理下的地温较CK散失更缓慢,有一定保温效果;不同覆盖方式下食葵的株高、茎粗和叶面积在各个生育期均表现为SF＞S＞CK,SF处理下湿基含水率也高于其他两种方式。从食葵生物产量和土壤贮水量结果分析,试验区食葵种植使用碎麦秸垫膜覆盖有较好的保墒增产效果。   相似文献   

6.
覆膜滴灌对玉米生长及苗期土壤温度的试验研究   总被引：1，自引：0，他引：1  
为了探索河套灌区玉米不覆膜滴灌对其产量及土壤理化性质的影响,2015年在内蒙古河套灌区中游开展了玉米不覆膜滴灌试验研究。定株测试玉米不同生育期的株高、茎粗和产量对比分析,得出:在苗期和拔节期,覆膜滴灌玉米株高和茎粗显著优于不覆膜处理,抽雄期后对玉米植株生长性状影响差异不显著,但不覆膜处理玉米产量较覆膜处理下降了15.87%;在玉米苗期,0~40cm耕层土壤,覆膜处理较不覆膜处理土壤温度平均增加了5.62℃。土壤耕层温度的提高为玉米生长提高良好的土壤环境。  相似文献   

7.
In semi-arid areas, crop growth is greatly limited by water. Amount of available water in soil can be increased by surface mulching and other soil management practices. Field experiments were conducted in 2005 and 2006 at Gaolan, Gansu, China, to determine the influence of ridge and furrow rainfall harvesting system (RFRHS), surface mulching and supplementary irrigation (SI) in various combinations on rainwater harvesting, amount of moisture in soil, water use efficiency (WUE), biomass yield of sweet sorghum (Sorghum bicolour L.) and seed yield of maize (Zea mays L.). In conventional fields without RFRHS, gravel-sand mulching produced higher biomass yield than plastic-mulching or straw-mulching. In plastic-mulched fields, an increasing amount of supplemental irrigation was needed to improve crop yield. There was no effect of RFRHS without plastic-covered ridge on rainwater harvesting when natural precipitation was less than 5 mm per event. This was due to little runoff of rainwater from frequent low precipitation showers, and most of the harvested rainwater gathered at the soil surface is lost to evaporation. In the RFRHS, crop yield and WUE were higher with plastic-covered ridges than bare ridges, and also higher with gravel-sand-mulched furrows than bare furrows in most cases, or straw-mulched furrows in some cases. This was most likely due to decreased evaporation with plastic or gravel-sand mulch. In the RFRHS with plastic-covered ridges and gravel-sand-mulched furrows, application of 30 mm supplemental irrigation produced the highest yield and WUE for sweet sorghum and maize in most cases. In conclusion, the findings suggested the integrated use of RFRHS, mulching and supplementary irrigation to improve rainwater availability for high sustainable crop yield. However, the high additional costs of supplemental irrigation and construction of RFRHS for rainwater harvesting need to be considered before using these practices on a commercial scale.  相似文献   

8.
The intake rate of the local Vertisol is very low (0.08 cm/h). Vertical mulch was used from 1971 to 1976 in order to improve infiltration. Higher moisture contents were recorded near the mulch. The favourable effects of mulch extended to 1.5 m on either side of the mulch row. Vertical mulching exerted a greater influence on crop yields under dry conditions than in normal and above normal seasons. Compared with low yields in control plots (grain: 0.2 q/ha (20 kg/ha); straw: 9.5 q/ha (950 kg/ha)) mulches spaced at 2, 4 and 8 m produced 3.9 q/ha of grain and 19.0 q/ha of straw under the extremely dry conditions of 1972–1973. However, the increase in grain and straw yields under wet conditions in 1973–1974 was only 47.2 and 15.0%, respectively. Averaged over dry and wet years, vertical mulching resulted in 45.1 and 37.9% higher grain and straw yields. The favourable effects of vertical mulching were found to last for 4 years. Considering dry and wet years, a spacing of 4 m was found to be ideal. Placing sorghum stubble as a vertical mulch to the top of the salt zone (30 cm) was found to be as good as placing it to a depth of 90 cm.  相似文献   

9.
Mulch resistance to water vapor transport   总被引：2，自引：0，他引：2  
Mulches augment soil moisture availability to plants by restraining direct evaporation of soil water. Yet, in field conditions wind decreases their resistance to water vapor transport, diminishing their efficiency as a water conservation measure. The relation between vapor transport resistance and wind speed was investigated in a wind tunnel where air flow was turbulent. The mulch material was chopped straw with bulk densities of 31 and 37 kg m−3, and chemically stabilized aggregates segregated in diameter classes 1-2, 2-4, 4-8, 8-11.2 mm, in layers 10-100 mm thick. The resistance decreased exponentially with increasing wind speed from the molecular diffusion value at zero wind speed, suggesting that turbulence penetrates the pores of the mulch and drives convective water vapor transport. Resistance rose exponentially with increasing layer thickness, a mirror reflection of the turbulence decay profile. Higher bulk density of the straw and finer aggregates augmented the resistance. The convective component of the vapor transport resistance was related to mulch area index, defined as the surface area of the solid elements of mulch per unit covered ground area. This procedure merged the effect of layer thickness and that of straw bulk density or aggregates size into a single function, indicating that friction forces proportional to internal area of the solid fabric restrain the penetration of momentum in the porous medium. Two-layered mulches combining straw and aggregates have a higher resistance than the sum of the resistances of the individual components as is expected from the attenuation of convection in the top layer. The functions derived in this study can serve as input for models evaluating the impact of mulches on soil water balance.  相似文献   

10.
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11.
不同覆盖和水分处理对夏玉米生长发育和耗水特性的影响   总被引：4，自引：1，他引：3  
在防雨棚下的测坑,研究了夏玉米在3种土壤水分下限控制条件下(占田间持水量的75%、65%和55%)不覆盖、地膜覆盖以及秸秆覆盖对作物生长发育、产量、耗水量以及水分利用效率(WUE)的影响.结果表明:地膜和秸秆覆盖的株高、叶面积指数、产量和水分利用效率均大于不覆盖;高水分秸秆覆盖的株高和叶面积指数高于地膜覆盖和无覆盖,中、低水分时地膜覆盖的株高和叶面积指数高于秸秆覆盖和无覆盖;中水分秸秆覆盖的增产效果最好,增产率为44.80%,高水分地膜覆盖的增产效果最差,增产率仅为9.32%;高、中水分条件下地膜覆盖的WUE提高率最大,分别为19.09%和50.64%,而低水分条件下秸秆覆盖的WUE提高率最大.由此可见,地膜和秸秆覆盖效应各有优势,土壤水分下限控制在田间持水量的65%时覆盖效果最佳.  相似文献   

12.
开沟覆膜滴灌条件下土壤水、温变化规律研究   总被引：1，自引：0，他引：1  
新疆是中国葡萄重要的生产基地,但每年因盐碱与缺水导致减产现象严重。开沟覆膜滴灌技术结合膜下滴灌与开沟技术优点,理论上可有效改善作物生长的水土环境。为研究桁架葡萄下开沟覆膜滴灌技术对土壤水分与温度变化的影响,在石河子147团6连试验地用EM50仪器开展土壤水分、温度监测试验。研究结果表明:①在开沟模式为20 cm×100 cm,灌水定额为300 m3/hm~2时,无论是膜中还是膜边,灌水前后土壤含水量维持在0.22~0.38,满足作物根系吸水。加大灌水定额,在覆膜影响下,滴灌带表面积水区面积增大,使得在滴头下方形成饱和区增大;随着开沟深度的增大,覆膜中土壤含水量变化不明显,覆膜边呈下降趋势。②温度监测表明,无论是温度上升期(12时),还是夜间下降期(24时),土体温度变化幅度均在15~31℃,给葡萄生长提供良好的温度环境,利于葡萄产量与品质的提高。  相似文献   

13.
不同覆盖方式对土壤水肥热状况以及玉米产量影响   总被引：2，自引：0，他引：2  
【目的】阐明不同覆盖方式对调节土壤水肥热状况以及增加玉米产量的影响。【方法】设置地膜覆盖、玉米秸秆覆盖和不覆盖3种方式,研究了不同覆盖方式对土壤含水率、土壤养分、土壤温度与玉米产量的影响。【结果】在玉米的生长前、中期,秸秆覆盖与地膜覆盖处理的保墒效果均优于不覆盖处理,其中0~60 cm土层土壤含水率差异明显;玉米进入成熟期后,秸秆覆盖处理0~60 cm土层含水率显著高于地膜覆盖和不覆盖处理,平均高8.23%和22.41%。秸秆覆盖能够促进浅层土壤养分量的提高,相较于不覆盖,秸秆覆盖的速效钾与有效磷量分别增加了15.11%、85.13%;相比地膜覆盖和不覆盖,生长前期秸秆覆盖温度更高,生长期和成熟期秸秆覆盖温度更低。地膜覆盖、秸秆覆盖的玉米产量分别比不覆盖高24.02%、24.90%,差异显著(P<0.05)。【结论】玉米秸秆覆盖能够提高土壤养分与水分,调节土壤温度,增加玉米产量。  相似文献   

14.
In Northern India, insufficient soil moisture and excessively high soil temperatures are reported to restrict growth of crops during the hot, dry months of April–June. A 3-year field experiment was conducted to evaluate the effects of three irrigation schedules based on ratios of 0.50, 0.75 and 1.00 times pan evaporation, and two levels of paddy straw mulch of 0 and 6 tons/ha on yield and quality of sugarcane for a sandy loam. The differential irrigations were restricted to 10–12 weeks before the monsoon season.Both irrigation and straw mulching had favourable effects on plant height and yield. Cane yield increased by an average of 13.8% for the 1.00 over the 0.50 times pan evaporation. Similarly, yield averaged 13.8% higher with mulch than without it. Interestingly, the pan evaporation ratio of 0.50 with mulch gave a higher yield than the ratio 1.00 without mulch. For the same yield, irrigation under mulching averaged 34 cm less than under no mulch. These beneficial effects were attributed to better soil moisture and temperature regimes with mulching. Irrigation and mulching had no effect on the quality of cane juice. These results indicate that straw mulching and early season irrigation to sugarcane based on 1.00 times pan evaporation is a promising practice for increasing sugarcane production in subtropical areas.  相似文献   

15.
地膜机械化覆盖栽培技术是采用铺膜机对作物栽培方式的一种改变,由于地膜覆盖保墒、集水、增温的作用,能大幅度提高作物的生长周期,给农户带来效益,但由于铺放的地膜如不及时、妥善回收,就会造成污染,带来严重的后果。  相似文献   

16.
Gravel and sand mulch is an effective practice in conserving soil and moisture. However, the proportion of different particle size in this kind of mulch layer is an important factor to be considered in order to obtain optimal results from this practice. From 2005 to 2007, a series of experiments including one with watermelon were conducted in the semi-arid Loess Plateau of northwest China to determine the influence of particle size and its proportion in mulch layer on soil temperature, evapotranspiration, water use efficiency (WUE) and watermelon (Citrullus lanatus L.) yield. The treatments in no-watermelon experiments included particle sizes classified as <0.3, 0.3-1, 1-2, 2-4, 4-6, 6-8 and 8-10 cm mesh size or various rates of 2-6 cm pebble accounting for 0, 10, 20, 30, 40, 50, 60 and 70% with 30% 1-2 cm gravel-sand in mulch layer (as well as correspondingly decreasing sand proportions). The watermelon experiment included three particle sizes, 0.3-1, 1-2 and 2-6 cm. Soil temperature at 8:00 h was highest for the 1-2 cm treatment, and the daily average temperature at 14:00 h was highest for the 0.3-1 cm treatment. Soil temperature decreased with particle size increasing due to porosity enlarging. The relationship between soil temperature and particle size followed a quadratic or cubic curve. Soil temperature was increased by gravel-sand mulch plus plastic film. The increment of soil temperature was larger especially for 1-4 cm particle size. In the gravel-sand mulch layer having different size particles, the greater percentage being of 2-6 cm pebbles, increases porosity, and lowers soil temperature, and causes more evaporation. The results of the watermelon experiment showed that soil moisture before seeding would not affect the yield during the years of using gravel mulch. Watermelon yield and WUE were higher for 1-2 and 0.3-1 cm treatments than 2-6 cm treatments in later experiments during 2006 and 2007. In conclusion, 2-6 cm large size particles would not account for much in gravel-sand mulching layer. It would be better if the percentage of 2-6 cm particles was less than 30%.  相似文献   

17.
不同颜色地膜覆盖对玉米土壤水热状况及产量的影响   总被引：6，自引：0，他引：6  
针对河套灌区普通农用白色地膜造成的玉米早衰现象,试验设置黑色地膜覆盖、白色地膜覆盖和不覆膜3个处理,研究了不同颜色地膜覆盖对土壤水热效应及玉米产量和水分利用效率的影响。结果表明:黑色地膜在各生育期内0~15 cm土壤温度要显著的低于白色地膜覆盖(P0.05),平均低0.77℃,且在一日内气温最高时段差异更为明显,这也使得玉米免遭高温的危害,有利于其正常生长发育。黑色地膜覆盖条件下0~100cm土壤含水率与白色地膜覆盖无显著性差异(P0.05),具有较好的土壤保墒效果,但0~60 cm土壤含水率均显著或极显著高于不覆膜处理(P0.05或P0.01)。黑色地膜显著提高了玉米百粒重和产量,平均较白色地膜和不覆膜处理高百粒重平均高6.46%、9.86%,产量平均高5.99%和25.60%。黑色地膜覆盖明显提高了作物水分利用效率,平均较白色地膜和不覆膜处理高4.76%和34.24%。因此,玉米黑色地膜覆盖的农作措施较适宜在灌区推广应用。  相似文献   

18.
在宁南旱区,采用免耕、深松、翻耕结合秸秆、地膜等覆盖耕作措施,以翻耕不覆盖为对照,研究覆盖耕作模式下休闲期土壤的蓄水保墒效果、马铃薯生育期土壤水分的变化特征及对作物生长、产量及水分利用效率的影响.结果表明:在休闲末期,不同覆盖耕作处理下0~200 cm土层土壤蓄水量均比休闲初期明显提高.与翻耕不覆盖处理相比,免耕覆盖地膜、深松覆盖地膜和翻耕覆盖地膜处理0~200 cm土层土壤蓄水量分别比对照处理提高7.6%,9.3%和8.0%.马铃薯生育前期,覆盖地膜结合不同耕作措施下0~200 cm土层土壤蓄水量最高,生育中后期覆盖秸秆结合不同耕作处理对0~200 cm土层土壤保水效果最佳.覆盖地膜结合不同耕作处理能促进马铃薯生育前期的生长,生育中后期以覆盖秸秆结合不同耕作处理促进作用最为显著.不同覆盖耕作处理均能提高马铃薯的产量和水分利用效率,增产效果以免耕覆盖秸秆、深松覆盖秸秆和翻耕覆盖秸秆处理最为显著,分别较对照组增产51.2%,42.8%和35.3%,水分利用效率分别比对照组提高50.0%,42.3%和32.3%.可见,覆盖秸秆结合不同耕作处理的增产效果和提高水分利用效率最高.  相似文献   

19.
在2个灌水水平下（I1：高水,I2：低水）以不同滴灌带间距（A1：1m,A2：0.5m）与覆膜方式（M1：全膜覆盖,M2：半膜覆盖）进行2a田间试验,结合作物产量、作物水分利用效率（WUE）以及产投比筛选适宜的膜下滴灌模式,并利用产量水分敏感系数（ky）确定最优的膜下滴灌模式。结果表明：在低频灌溉模式下,部分覆膜处理的蒸腾（ET）高于全覆膜处理,而产量和WUE低于全覆膜处理。尽管滴灌带间距对ET的影响不明显,然而在高水处理下,“一管单行”作物的产量与WUE高于“一管双行”。高频灌溉模式下,作物产量及WUE对灌溉量、覆膜方式、滴灌带间距的响应呈现耦合性。低频灌溉条件下,ky对灌溉量及滴灌带间距的响应均不显著,而部分覆盖处理WUE低,ky高,对水分胁迫的响应敏感。高频灌溉条件下,覆膜方式、灌溉量以及滴灌带间距均对ky 产生影响。高频灌溉条件下,ky能对经WUE筛选出的膜下滴灌处理进行进一步的优选。基于ky的结果,结合产量、水分利用效率与产投比,建议在高频灌溉条件下采取“全膜低水+一管双行”模式或“半膜高水+一管单行”模式,在低频灌溉条件下采取全膜高水模式。  相似文献   

20.
针对塑料地膜对农业生产造成的严重污染问题,运用对照处理方法,探讨了液体地膜覆盖对夏玉米生长发育及产量等方面的影响。结果表明,液膜覆盖使夏玉米株高和茎粗均比对照偏大,其中,低水分处理下差异最为显著。夏玉米叶面积指数低水分处理时液膜覆盖在生育前期较对照偏大,生育后期偏小;而中、高水分下液膜覆盖叶面积指数在整个生育期内均比对照偏大。液膜覆盖使夏玉米光合速率和蒸腾速率显著增大,有利于光合产物的形成。低水分处理下液膜覆盖增产效果最好,增产率达到56.97%,产投比为1.695,高水分下液膜覆盖增产效果最差,增产率仅为15.57%,液膜覆盖产投比小于对照。研究认为,夏玉米液膜覆盖能有效抵抗干旱逆境从而达到节水增产的显著效果。  相似文献   

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