Variability of Soil Moisture and Its Relationship with Surface Albedo and Soil Thermal Parameters over the Loess Plateau

Data from July 2006 to June 2008 observed at SACOL （Semi-Arid Climate and Environment Observatory of Lanzhou University, 35.946°N, 104.137°E, elev. 1961 m）, a semi-arid site in Northwest China, are used to study seasonal variability of soil moisture, along with surface albedo and other soil thermal parameters, such as heat capacity, thermal conductivity and thermal diffusivity, and their relationships to soil moisture content. The results indicate that surface albedo decreases with increases in soil moisture content, showing a typical exponential relation between the surface albedo and the soil moisture. The heat capacity, the soil thermal diffusivity, and soil thermal conductivity show large variations between Julian day 90-212 and 450-578. The soil thermal conductivity is found to increase as a power function of soil moisture. Soil heat capacity and soil thermal diffusivity increase with increases in soil moisture. The SACOL observed soil moisture are also used to validate the AMSR-E/AQUA retrieved soil moisture and there is good agreement between them. The analysis of the relationship between satellite retrieved soil moisture and precipitation suggests that the variability of soil moisture depends on the variation of precipitation over the Loess Plateau.

An evaluation of soil moisture from AMSR-E over source area of the Yellow River, China

In this study,in-situ soil moisture measurements are used to evaluate the accuracy of three AMSR-E soil moisture prod ucts from NASA(National Aeronautics and Space Administration),JAXA(Japanese Aerospace Exploration Agency)and VUA(Vrije University Amsterdam and NASA)over Maqu County,Source Area of the Yellow River(SAYR),China.Re sults show that the VUA soil moisture product performs the best among the three AMSR-E soil moisture products in the study area,with a minimum RMSE(root mean square error)of 0.08(0.10)m3/m3 and smallest absolute error of 0.07(0.08)m3/m3 at the grassland area with ascending(descending)data.Therefore,the VUA soil moisture product is used to describe the spatial variation of soil moisture during the 2010 growing season over SAYR.The VUA soil moisture product shows that soil moisture presents a declining trend from east south(0.42 m3/m3)to west north(0.23 m3/m3),with good agreement with a general precipitation distribution.The center of SAYR presents extreme wetness(0.60 m3/m3)dur ing the whole study period,especially in July,while the head of SAYR presents a high level soil moisture(0.23 m3/m3)in July,August and September.

Impact of Smart Valley on Soil Moisture Content and Rice Yield in Some Lowlands in Burkina Faso

To reduce the impact of rainfall variability on lowland rice yields, Burkina Faso state develops lowlands for small rice farmers. However, the high cost of these infrastructures makes impossible to duplicate them to satisfy the needs which are enormous. The Smart-Valley technology which is actually popularized in certain coastal countries of West Africa would therefore be a boon to increase the productivity of the Sudanese lowlands if it well regulates runoff. The object of this study was therefore to know if smart valley technology could increase soil moisture in order to mitigate the impact of drought’s pockets on rice cultivation in the Sudanese lowlands. The experiment takes place in three lowlands during the rainy seasons 2018 and 2019. The climatic data comes from the meteorological stations in the study areas as well as those installed on the sites. The infiltration measurements were carried out using the double Muntz ring. The soil moisture measurement device consisted of a smart valley area of 5 ha and an undeveloped area of 5 ha per site. Sixteen tubes were installed per lowland allowing the humidity to be measured at a depth of 10, 20, 30, 40 cm using a probe. Four rice varieties, Orylux6, FKR62N, FKR19 and FKR64 were tested on plots of 0.25 ha per variety in the smart valley and undeveloped parts. The results showed that the humidity level was 12% higher in the smart-valley plots throughout the cycle compared to the unmanaged area. In addition, humidity decreases rapidly in unmanaged plots as rain becomes increasingly scarce. Finally, the smart-valley development allowed an average increase in rice yields of 21% compared to the average yield of undeveloped plots.

Growth characteristics of multipurpose tree species, crop productivity and soil properties in agroforestry systems under subtropical humid climate in India

Multipurpose tree species （MPTs） were studied in an agroforestry arboretum under subtropical humid climate in Northeast India. Out of 12 MPTs planted under agroforestry systems, Acacia auriculiformis in spacing of 2 m × 2 m （2500 stems·hm^-2） could have the potentiality to meet the timber/fuelwood requirement due to its high wood production of 635 m^3·hm^-2 with mean annual increment （MAI） of 2.54×10^-2 m^3.treel.a^-1 in a short rotation period of 10 years. Thus, A. auriculiformis is a short rotation forest tree species suitable to grow in subtropical humid climate. On the other hand, at 16 years of age, Eucalyptus hybrid and Michelia champaca in spacing of 3 m × 3 m （1111 stems.hm^2） produced appreciably high timber volume of 315 m^3.hm^-2 and 165 m^3.hm^-2 with MAI of 1.77×10^-2 m^3.tree^-1·a^-1 and 0.92×10.2 m^3.tree^-1.a^-1, respectively. At 16 years of age, Gmelina arborea produced a timber volume of 147 m^3.hm^-2 with MAI of 1.47×10^-2 m^3.tree^-1.a^-1 followed by Samania saman （140 m^3.hm^-2）, Albizziaprocera （113 m^3·hm^-2） and Tectona grandis （79 m3.hm^-2） with MAI of 1.40, 1.13 and 0.78 × 10^-2 m^3 .tree^-1a^-1, respectively in 4 m × 4 m spacing （625 stems.hm^-2）. Gliricidia maculata and Leucaena leucocephala could be used as live fences around the farm boundary to supply their N-rich leaves for mulch as well as manure to crops. In agroforestry arboretum, direct seeded upland rice （Oryza sativa - variety, AR-11）, groundnut （Arachis hypogaea - variety, JL-24） and sesamum （Sesamum indicum - variety, B-67） were grown during the initial period upto 8 years of tree establishment. Under other MPTs, there was a reduction in crop productivity as compared to open space. After 8 years of tree establishment, horti-silvi and silvi-pastoral systems were developed and pineapple （Ananas comosus - variety Queen）, turmeric （Curcuma longa -variety RCT -1） and cowpea （Vigna sinensis - variety Pusa Barsati） as forage crop were raised. The productivity of pineapple, turmeric and cowpea was comparatively high under Azadirachta indica. The productivity of horticultural and forage crops in association with trees such as G. arborea, A. procera, S. saman, T. grandis and M. champaca of high timber value could be harnessed as viable agroforestry systems. Changes in soil properties were also monitored. Amelioration of soil acidity, increase in soil organic carbon, and enhanced humification of soil humus, high nutrient availability, low soil erodibility and high surface soil （0-15 cm） moisture availability were noted in soils under MPTs.

THE EFFECT OF LAND USE CHANGES ON SOIL CONDITIONS IN ARID REGION

Land use change may influence a variety of natural and ecological processes, including soil nutrient, soil moisture, soil erosion, land productivity and biodiversity. In this paper, 9 typical land use patterns sustainable 15－ 20 years have been chosen to study the effect of different land use patterns on soil nutrient, soil erosion, soil moisture, saline and so on. We drew conclusions as follows: Firstly, it is clear of the effect of land use change on soil. Land use change results in the decline of soil nutrient and erosion rate, but the increase of land productivity; secondly, the erosion rate and the rate of vegetation cover is the subtractive correlativity. It reflects the effect of soil erosion on land productivity. It is clear of the positive correlativity between land productivity and soil moisture and explains the role of land surface vegetation to preventing aridity in the northwestern China; lastly, it is feasible to develop animal husbandry properly in arid region. The topgallant land use pattern is the combination of forest and meadow in arid region. The rational land use may prevent or weaken the intensity of soil erosion in a certain extent. Therefore, activities accorded with ecological principal such as readjustment of land use structure, rational reclamation along with adoption of prevention and control measures can reverse land degradation process.

Improvement in winter wheat productivity through regulating PSⅡ photochemistry,photosynthesis and chlorophyll fluorescence under deficit irrigation conditions

Deficit irrigation is critical to global food production,particularly in arid and semi-arid regions with low precipitation.Given water shortage has threatened agricultural sustainability under the dry-land farming system in China,there is an urgent need to develop effective water-saving technologies.We carried out a field study under two cultivation techniques:(1) the ridge and furrow cultivation model(R);and(2) the conventional flat farming model(F),and three simulated precipitation levels(1,275 mm;2,200 mm;3,125 mm) with two deficit irrigation levels(150 and 75 mm).We demonstrated that under the ridge furrow(R) model,rainfall harvesting planting under 150 mm deficit irrigation combined with 200 mm simulated precipitation can considerably increase net photosynthesis rate(P_(n)),quantum yield of PSII(ΦPSⅡ),electron transport rate(ETR),performance index of photosynthetic PSII(F_(v)/F_(m)′),and transformation energy potential of PSII(F_(v)/F_(o)).In addition,during the jointing,anthesis and grain-filling stages,the grain and biomass yield in the R model are 18.9 and 11.1% higher than those in the flat cultivation model,respectively,primarily due to improved soil water contents.The winter wheat fluorescence parameters were significantly positively associated with the photosynthesis,biomass and wheat production.The result suggests that the R cultivation model with irrigation of 150 mm and simulated precipitation of 200 mm is an effective planting method for enhancing P_(n),biomass,wheat production,and chlorophyll fluorescence parameters in dry-land farming areas.

Assessing remotely sensed and reanalysis products in characterizing surface soil moisture in the Mongolian Plateau

Soil moisture(SM)plays a crucial role in the dynamics of coupled atmosphere,water,energy,and carbon cycles.In this study,the spatiotemporal distribution and variations of SM in the Mongolian Plateau were investigated for the period of 1982-2018 based on four gridded SM datasets.Taking the observed SM from 33 monitoring stations as a reference,the reliability of these four gridded products was validated,and the three-cornered hat(TCH)method was also applied to evaluate their uncertainties.Major results indicated that all these four products underestimated the SM in this region at different levels.The ERA-Interim SM performed much better than other three products,with a higher R of 0.53 and lower ubRMSE of 0.0378 m^(3)·m^(−3).Except for ECV,the surface SM exhibited a decreasing trend at−0.0004 to−0.0008 m^(3)·m^(−3)/decade in the warm season(from April to October)over the past 37 years.The greatest decreases in SM occurred in the summer season.Precipitation change plays a more important role in explaining the variations of SM than temperature reported by partial correlation analysis.The results of this study will benefit our understanding of the climate change effects and the protection of the ecological systems in this region.

Applied methods for studying the relationship between climatic factors and cotton production

This study investigates the statistical relationship between climatic variables and aspects of cotton production (G. barbadense), and the effects of climatic factors prevailing prior to flowering or subsequent to boll setting on flower and boll production and retention in cotton. The effects of specific climatic factors during both pre-?and post-anthesis periods on boll production and retention are mostly unknown. However, by determining the relationship of climatic factors with flower and boll production and retention, the overall level of production can be possibly predicted. Thus, an understanding of these relationships may help physiologists determine control mechanisms of production in cotton plants. Also, the study covers the predicted effects of climatic factors during convenient intervals (in days) on cotton flower and boll production compared with daily observations. Further, cotton flower and boll production as affected by climatic factors and soil moisture status has been considered. Evaporation, sunshine duration, relative humidity, surface soil temperature at 1800 h, and maximum air temperature, are the important climatic factors that significantly affect flower and boll production. The least important variables were found to be surface soil temperature at 600 h and minimum temperature. The five-day interval was found to be more adequately and sensibly related to yield parameters. Evaporation, minimum humidity and sunshine duration were the most effective climatic factors during preceding and succeeding periods on boll production and retention. There was a negative correlation between flower number and boll production and either evaporation or sunshine duration, while that correlation with minimum relative humidity was positive. The soil moisture status showed low and insignificant correlation with flower and boll production. Higher minimum relative humidity, short period of sunshine duration, and low temperatures enhanced flower and boll formation.

Decoupling between Plant Productivity and Growing Season Length under a Warming Climate in Canada’s Arctic

Given the short duration of growing season in the Arctic, a strong correlation between plant productivity and growing season length (GSL) is conventionally assumed. Will this assumption hold true under a warming climate? In this study, we addressed the question by investigating the relationship between net primary productivity of leaves (NPPleaf) and GSL for various tundra ecosystems. We quantified NPPleaf and GSL using long-term satellite data and field measurements. Our results indicated that the relationship was not significant (i.e., decoupled) for 44% to 64% of tundra classes in the southern Canadian Arctic, but significant for all classes in the northern Canadian Arctic. To better understand the causes of the decoupling, we further decomposed the relationship into two components: the correspondence of interannual variations and the agreement of long- term trends. We found that the longer the mean GSL for a tundra class, the poorer the correspondence between their interannual variations. Soil moisture limitation further decoupled the relationship by deteriorating the agreement of long-term trends. Consequently, the decoupling between NPPleaf and GSL would be more likely to occur under a warming climate if the tundra class had a mean GSL > 116 (or 123) days with a dry (or moist) soil moisture regime.

黄河流域植被总初级生产力对持续性干旱水分亏缺的响应

利用植被总初级生产力和高精度分层土壤含水量数据分析了2001—2020年黄河流域生长季总初级生产力时空分布和变化特征,量化了流域不同深度土壤湿度之间的相关关系,探究了不同植被类型在生长季的总初级生产力对土壤连续水分亏缺事件的响应关系。结果表明:黄河流域总初级生产力空间上呈东高西低、南高北低的分布特征,生长季耕地累积总初级生产力最大、林地次之、草地最小,研究期内流域总初级生产力整体呈上升趋势,耕地相对增速最大、草地次之、林地最小;流域土壤湿度在空间和时间上均有显著差异,表层土壤含水量波动对深层土壤含水量的影响随深度增加而减小,林地和耕地表层与深层土壤含水量的相关性远高于草地;流域草地和耕地总初级生产力对土壤水分的深度敏感区间为0~40 cm,林地的深度敏感区间为0~100 cm,在深度敏感区间内,随着土壤连续水分亏缺天数的增加,草地和耕地总初级生产力依次经历短暂平稳、加速下降、降速趋缓的变化过程,而林地总初级生产力则表现出短暂下挫、长时间平稳、加速下降的变化特征。

全球旱地饱和水汽压差和根区土壤水分变化对植被生产力的影响及其成因

旱地约占全球陆地面积的40%,而水分是旱地植被生长的一大限制要素。尽管土壤水分与饱和水汽压差对植被生长的重要性已经得到了广泛证实,然而目前二者对植被生产力影响的空间异质性及其形成因素仍未得到深入研究,这对研究旱地生态系统对气候变化的响应带来了挑战。为了填补这一认知空白,研究收集了多源气象、根区土壤含水率和总初级生产力产品,基于随机森林算法量化了植被总初级生产力对根区土壤含水率和饱和水汽压差的敏感性,结合土地覆盖数据和分档平均方法分析了敏感性空间异质性的形成机制。结果表明:全球旱地饱和水汽压差与植被生产力总体呈显著上升趋势;根区土壤水分对植被生长的影响以正效应主导,饱和水汽压差对植被生长的影响以负效应主导;相较于森林和灌木,饱和水汽压差对植被生长的负效应及根区土壤含水率对植被生长的正效应在农田、草地和苔原及半干旱区更为强烈;植被生产力对饱和水汽压差和根区土壤水分的敏感性在数量上总体呈显著的线性负相关性。综上,植被种类和气候条件是导致全球旱地植被生产力对土壤水分和饱和水汽压差敏感性空间异质性的重要因素。

应用集合卡尔曼滤波算法对土壤呼吸速率同化及NEP估算

为了对净生态系统生产力(NEP)进行准确估算,以长白山通量观测站观测数据为基础,构建土壤温度、湿度耦合因子的更新模型(线性函数、指数函数、二次式函数),结合集合卡尔曼滤波算法(EnKF)获取高精度土壤呼吸速率数据,应用陆地生态系统碳循环综合模型(InTEC模型)准确估算NEP。结果表明:二次式模型的EnKF算法同化结果估算效果最好,决定系数(R^(2))为0.782,均方根误差为52.90 g·m^(-2)·a^(-1);指数模型EnKF算法同化结果估算值的R^(2)为0.755,均方根误差为56.47 g·m^(-2)·a^(-1);线性模型EnKF算法同化结果估算值的R^(2)为0.742,均方根误差为62.80 g·m^(-2)·a^(-1)。选取二次式模型优化后的土壤呼吸速率数据,InTEC模型模拟长白山通量观测站长时间序列净生态系统生产力的R^(2)为0.900,均方根误差为61.77 g·m^(-2)·a^(-1);InTEC模型模拟东北三省森林生态系统2003—2010年的净生态系统生产力年均值,由初始模拟的30.07 g·m^(-2)·a^(-1),经EnKF算法更新后提升到176.87 g·m^(-2)·a^(-1)。因此,采用EnKF更新土壤温度-湿度耦合因子获取的土壤呼吸速率数据,能够提高InTEC模型估算NEP的精度,为大区域尺度森林生态系统NEP估算提供技术支持。

人工林种植和生长对黄土高原生态系统固碳和水文调节功能的影响——基于遥感时序分析证据

随着生态恢复工程的进展,黄土高原人工林种植面积不断增加,黄土高原人工林生态系统服务功能的响应变化仍存在争议。基于黄土高原人工林的时空分布和种植年份信息,从生态系统净初级生产力(NPP)、蒸散发(ET)以及土壤含水率(SMC)三个维度评估黄土高原地区人工林生态系统固碳和水文调节服务功能的动态变化及其对天然林和整个区域生态系统功能的影响,并进一步研究2000—2020年间人工林林龄对生态系统服务功能的影响。天然林的NPP相对于整个区域的百分比基本保持不变,维持在21%左右;而人工林的NPP相对于整个区域的百分比显著增加,并在2009年超过了天然林,成为黄土高原NPP增加的主要来源。人工林占整个区域的ET百分比和SMC百分比均显著增加,分别由不到2%增长至13.9%、1.5%上升至11.8%。至2015年,黄土高原人工林的ET和SMC已经逐步趋于稳定。随着林龄增大,SMC变化速率和变化量不断下降。ET与林龄成正相关,而SMC与林龄负相关,表明具有不同年龄结构的人工林将有效减弱树木生长所引起的土壤干旱的影响。尽管黄土高原人工林林龄与NPP、ET和SMC变化速率和变化量之间存在显著相关性(P<0.01),但由于现阶段此地区人工林多为幼龄林和中龄林,未来这种显著相关关系是否持续有待进一步研究。

How do greenhouse gas emissions vary with biofertilizer type and soil temperature and moisture in a tropical grassland?

Greenhouse gases are known to play an important role in global warming.In this study,we determined the effects of selected soil and climate variables on nitrous oxide(N2O),methane(CH4),and carbon dioxide(CO2)emissions from a tropical grassland fertilized with chicken slurry,swine slurry,cattle slurry,and cattle compost.Cumulative N2O emissions did not differ between treatments and varied from 29.26 to 32.85 mg N m^-2.Similarly,cumulative CH4 emissions were not significantly different among the treatments and ranged from 6.34 to 57.73 mg CH4 m^-2.Slurry and compost application induced CO2 emissions that were significantly different from those in the control treatment.The CH4 conversion factors measured were 0.21%,1.39%,4.39%,and 5.07%for cattle compost,chicken slurry,swine slurry,and cattle slurry,respectively,differing from the recommendations of the Intergovernmental Panel on Climate Change(IPCC).The fraction of added Nemitted as N2O was 0.39%,which was lower than the IPCC default value of 2%.Our findings suggest that N2O emissions could be mitigated by replacing synthetic fertilizer sources with either biofertilizer or compost.Our results indicate the following:N2O emission was mainly controlled by soil temperature,followed by soil moisture and then soil NH^"content;CH4 fluxes were mainly controlled by soil moisture and chamber headspace temperature;and CO2 fluxes were mainly controlled by chamber headspace temperature and soil moisture.

保水剂对冬小麦不同生育阶段土壤水分及利用的影响

为探明保水剂施用后对冬小麦不同生育阶段水分利用的作用机理,在豫西丘陵旱作区,通过大田试验,研究了保水剂对冬小麦不同生育阶段的保水、作物的耗水特征、水分利用效率等的影响。结果表明:保水剂提高了冬小麦不同生育阶段0～100cm土层的土壤含水量、促进了生物量的积累、降低了小麦耗水量、提高了小麦产量和水分利用效率。各处理中,60和90kg/hm2处理的土壤含水量及储水量均较其他处理高,而耗水量最低。播种-拔节期,保水剂用量越高干物质积累越显著;拔节-孕穗期及灌浆-收获期,60kg/hm2处理较对照增加的干物质量最高;而孕穗-灌浆期,30kg/hm2干物质量增加最为显著。各生育阶段,除孕穗-灌浆期外,60kg/hm2处理的水分利用效率均较高。最终,60kg/hm2处理的产量和水分利用效率均最高,较对照增产47.4%,水分利用效率增加10.6kg/(mm·hm2)。

新疆库尔勒市土地利用变化对土壤性状的影响研究

土地利用与土地覆被变化是全球变化研究的热点问题。在新疆库尔勒市选择土地利用变化后已持续利用 1 5～ 2 0 a的 9种典型利用方式 ,1 1个剖面 ,与荒漠、原始胡杨林 2种参照利用方式 3个标准剖面进行对比分析。结果显示土地利用变化对土壤养分、土壤盐分、土壤侵蚀、土壤水分和土地生产力有明显的影响 ,荒漠开垦后土壤养分呈下降趋势 ,土壤侵蚀强度也呈下降趋势 ,土地生产力与土壤水分含量呈上升趋势。同时发现土壤侵蚀强度与土地生产力呈负相关关系 ,土地生产力与土壤水分呈正相关关系。林、草有利于保护干旱区生态环境 ,调整土地利用结构 ,合理开垦 ,加之预防和治理措施在一定程度上可防止或减弱土地退化 (荒漠化 )

气候变化对太行山土壤水分及植被的影响

在太行山低山区将自然植被移入蒸渗仪,观察当降水分别为常年平均降水量的80%、90%、100%、110%和120%等5种处理条件下,植被生产力和土壤的不同反映。研究发现:受验植被对降水反映敏感,降水每增加10%,植被生产力增加15%左右,预示未来全球变化导致的降水变化会对太行山低山区植被产生影响。同时在利用野外实验结果对WAVES模型进行验证的基础上,模拟了不同温度和降水变化情景下,土壤水分的可能变化趋势。结果表明:增温和减少降水对土壤水分负作用明显,尽管降水增加可改善土壤的水分供应状况,但降水增加10%对土壤水分的正面影响,大体被3 oC的增温抵消。由于模型模拟中采用的是与目前没有改变降水条件的实验相同的植被(LAI),而植被生长在太行山这一半湿润、半干旱地区又受土壤水分控制,因而估计未来气候变化情景下的植被变化与土壤水分的变化趋势相似。

果园生态系统生产力调控

以黄土沟壑区果园生态系统为研究对象,针对黄土高原果业生产波动性大,生态系统恶化等问题,通过调控果树的生殖生长量,研究了果园生态系统生产力调控及系统响应。结果表明:生产力水平高的处理对土壤深层的水分利用增强,但降低了土壤深层贮水量,从而进一步加重土壤干燥化程度;以生殖生长调控为手段的生产力调控能够显著改善果实的单果重、果实硬度、着色指数等外在品质,果品优果率可提高12.9%～23.5%;通过生产力调控,果业生产经济效益显著提高,果园生态系统健康状况得到维持,果树生产波动性缓解。确定挂果2.25×105个/hm2的生产力水平为黄土沟壑区盛果期果园生态系统的适宜生产力水平。

田间微集雨技术研究及应用

过去30a,田间微集雨技术逐渐发展成为黄土高原雨养农业区的主要耕作技术。自上世纪八十年代以来,不同田间微集雨及覆盖(地膜、砂石和秸秆)栽培技术在黄土高原不断更新换代,先后经历了垄沟无覆盖技术、平地覆盖技术、垄沟半覆盖技术和垄沟全覆盖技术等发展过程,特别是沟垄地膜全覆盖技术大面积推广和应用,为西北旱区粮食单产大幅度提高提供了强大的支撑作用。本文综述了田间微集雨技术的演变历程及对农田生态系统的影响及机理,归纳了垄沟和覆盖模式及播种方式对作物产量形成、水分利用效率、作物生理生态、土壤质量、土壤微生物、杂草、病虫害、覆盖物残留和作物物候等的影响,并分析了该技术的高产高效和生态风险以及两者的互作关系。文章最后还对该技术的高效性、可持续性和发展潜力进行了讨论,旨在对雨养农业生态系统的可持续管理提供理论指导。

黄土高原苹果基地土壤干燥化原因及其对策

黄土高原苹果基地果园土壤的干燥化相当广泛 ,已经成为影响苹果生产的主要问题。通过分析论证 ,综合各方面的事实和科学证据 ,认为果园土壤的干燥化是气候暖干化和苹果生产耗水两方面综合作用的结果。通过采取果园覆草技术 ,可以解决果园土壤的干燥化问题 ,提高下渗率 ,减少流失量 ,减少蒸发量 ,提高土壤含水量 ,同时提高土壤肥力 ,改善土壤理化性质与土壤结构 ,形成水、肥、气、热、生物因素平衡的生态系统 ,促进苹果生产的稳定发展。