Application of Mulching Materials of Rainfall Harvesting System for Improving Soil Water and Corn Growth in Northwest of China

The ridge and furrow rainfall harvesting（RFRH） system is used for dryland crop production in northwest of China.To determine the effects of RFRH using different mulching materials on corn growth and water use efficiency（WUE）,a field experiment was conducted during 2008-2010 at the Heyang Dryland Experimental Station,China.Four treatments were used in the study.Furrows received uncovered mulching in all RFRH treatments whereas ridges were mulched with plastic film（PF）,biodegradable film（BF） or liquid film（LF）.A conventional flat field without mulching was used as the control（CK）.The results indicated that the average soil water storage at depths of 0-200 cm were 8.2 and 7.3%,respectively higher with PF and BF than with CK.However,LF improved soil water storage during the early growth stage of the crop.Compared with CK,the corn yields with PF and BF were increased by 20.4 and 19.4%,respectively,and WUE with each treatment increased by 23.3 and 21.7%,respectively.There were no significant differences in corn yield or WUE with the PF and BF treatments.The net income was the highest with PF,followed by BF,and the 3-yr average net incomes with these treatments were increased by 2 559 and 2 430 CNY ha-1,respectively,compared with CK.BF and PF had similar effects in enhancing the soil water content,crop yield and net income.Therefore,it can be concluded that biodegradable film may be a sustainable ecological alternative to plastic film for use in the RFRH system in northwest of China.

Effects of Autumn Continuous Overcast and Rainfall on Harvesting Period of Semilate Rice and Countermeasures

Autumn continuous overcast and rainfall weather affects normal rice harvest and often causes higher rice output which is not accompanied by a higher income,and it is one of main agrometeorological disasters in harvesting period of middle and late rice in Hubei Province. Especially in recent years,plantation area of single-season rice in Hubei Province is larger,and it is mostly harvested from last dekad of September to middle dekad of October,and the opportunity of encountering autumn continuous overcast and rainfall in harvesting period is larger. From later period of last dekad of September to first and middle dekads of October,2017,continuous overcast and rainfall weather occurred in most areas of east Hubei Province,which caused serious influence on the harvesting of semilate rice. In this paper,adverse influence on semilate rice harvest by the autumn continuous overcast and rainfall was investigated and analyzed,and the suggestions on defending and reducing the harm of continuous overcast and rainfall in the harvesting period of semilate rice were proposed.

Ridge-furrow rainwater harvesting with supplemental irrigation to improve seed yield and water use efficiency of winter oilseed rape(Brassica napus L.)

Ridge-furrow rainwater harvesting （RFRH） planting pattern can lessen the effect of water deficits throughout all crop growth stages, but water shortage would remain unavoidable during some stages of crop growth in arid and semiarid areas. Supplemental irrigation would still be needed to achieve a higher production. Field experiments were conducted for two growing seasons （2012-2013 and 2013-2014）to determine an appropriate amount of supplemental irrigation to be applied to winter oilseed rape at the stem-elongation stage with RFRH planting pattern. Four treatments, including supplemental irrigation amount of 0 （I1）, 60 mm （I2） and 120 mm （I3） with RFRH planting pattern and a control （CK） irrigated with 120 mm with flat planting pattern, were set up to evaluate the effects of supplemental irrigation on aboveground dry matter （ADM）, nitrogen nutrition index （NNI）, radiation use efficiency （RUE）, water use efficiency （WUE）, and seed yield and oil content of the oilseed rape. Results showed that supplemental irrigation improved NNI, RUE, seed yield and oil content, and WUE. However, the NNI, RUE, seed yield and oil content, and WUE did not increase significantly or even showed a downward trend with excessive irrigation. Seed yield was the highest in 13 for both growing seasons. Seed yield and WUE in 13 averaged 3235 kg ha^-1 and 8.85 kg ha^-1 mm-1, respectively. The highest WUE was occurred in 12 for both growing seasons. Seed yield and WUE in 12 averaged 3089 kg ha^-1 and 9.63 kg ha^-1 mm^-1, respectively. Compared to 13, 12 used 60 mm less irrigation amount, had an 8.9% higher WUE, but only 4.5 and 0.4% lower seed yield and oil content, respectively. 12 saved water without substantially sacrificing yield or oil content, so it is recommended as an appropriate cultivation and irrigation schedule for winter oilseed rape at the stem-elongation stage.

Runoff Estimation for Suggested Water Harvesting Sites in the Northern Jordanian Badia

Jordan is characterized by severe weather conditions, therefore great temporal and spatial variations in rainfall;runoff and evaporation amounts are expected. Water harvesting has been practiced in Jordan throughout history for both irrigation and household purposes. A major research project was carried out in the Jordanian Badia on site selection criteria for rain water harvesting systems based on the integration between indigenous knowledge and the use of Geo-informatics. This work was followed by conducting a geophysical and soil investigation for five potential sites. In this study, GIS was used to investigate the potential of having enough runoff in the five selected sites to establish water harvesting dams based on rainfall, evaporation data and catchments’ areas for the selected sites. It was found that the estimated runoff that could be harvested on annual basis at these sites varies between 0.2 Million Cubic Meters (MCM) in Alaasra site to 0.82 MCM in Al-Manareh (Al-Ghuliasi) site. This indicates that these sites have the potential for small scale water harvesting that could be utilized by local livestock owners in the area to water their livestock.

Potential of rooftop rainwater harvesting to meet outdoor water demand in arid regions

The feasibility of rooftop rainwater harvesting （RRWH） as an alternative source of water to meet the outdoor water demand in nine states of the U.S. was evaluated using a system dynamics model developed in Systems Thinking, Experimental Learning Laboratory with Animation. The state of Arizona was selected to evaluate the effects of the selected model parameters on the efficacy of RRWH since among the nine states the arid region of Arizona showed the least potential of meeting the outdoor water demand with rain harvested water. The analyses were conducted on a monthly basis across a 10-year projected period from 2015 to 2024. The results showed that RRWH as a potential source of water was highly sensitive to certain model parameters such as the outdoor water demand, the use of desert landscaping, and the percentage of existing houses with RRWH. A significant difference （as high as 37.5%） in rainwater potential was observed between the projected wet and dry climate conditions in Arizona. The analysis of the dynamics of the storage tanks suggested that a 1.0-2.0 m3 rainwater barrel, on an average, can store approximately 80% of the monthly rainwater generated from the rooftops in Arizona, even across the high seasonal variation. This interactive model can be used as a quick estimator of the amount of water that could be generated, stored, and utilized through RRWH systems in the U.S. under different climate conditions. The findings of such comprehensive analyses may help regional policymakers, especially in arid regions, to develop a sustainable water management infrastructure.

集雨种植模式下种植密度与行距配置对小麦茎秆糖积累及倒伏性能的影响

【目的】分析沟垄集雨种植模式下不同种植密度和行距配置对小麦茎秆碳水化合物积累和抗倒伏性能的影响,明确适应于小麦沟垄集雨种植合理的密度及行距,为进一步稳定和提升小麦产量提供理论依据。【方法】以北方旱区主栽小麦品种西农979为试验材料,于2019—2021年在集雨种植模式下设置两个密度(低密度:180万株/hm^(2);高密度:225万株/hm^(2))和两种行距处理(等行距:20 cm;非等行距:12.5 cm﹕35 cm﹕12.5 cm),分析不同密度和行距对小麦植株中下部叶片的净光合速率、茎秆非结构性碳水化合物和结构性碳水化合物含量、茎秆折断弯矩和倒伏指数以及籽粒产量的影响。【结果】集雨种植模式下提高种植密度,小麦植株中下部叶片(倒三叶、倒四叶、倒五叶)的净光合速率(Pn)、茎秆基部第二节间非结构性碳水化合物(葡萄糖、果糖、蔗糖)和结构性碳水化合物(半纤维素、纤维素)含量、茎秆折断弯矩均明显降低,茎秆倒伏指数显著增高;而高密度种植条件下非等行距处理可改变植株各指标,其中,相较于高种植密度+等行距处理,植株倒三叶、倒四叶、倒五叶Pn明显提高,增幅分别为7.7%—16.5%、5.3%—37.7%、11.9%—24.9%,茎秆葡萄糖、果糖、蔗糖含量分别提高了9.8%—15.0%、8.8%—27.4%、8.2%—41.1%,半纤维素、纤维素含量分别增加4.5%—19.8%、5.9%—31.2%,茎秆折断弯矩提高4.8%—17.3%,茎秆倒伏指数降低10.9%—25.9%,小麦产量亦显著提高了13.5%—15.2%。相关分析表明,小麦茎秆基部节间葡萄糖、果糖、蔗糖含量与半纤维素、纤维素含量呈极显著正相关;小麦茎秆非结构性碳水化合物、结构性碳水化合物与小麦植株中下部叶片Pn及茎秆折断弯矩呈显著正相关,而与倒伏指数呈极显著负相关。【结论】集雨种植模式下,通过非等行距种植调节群体空间分布,可有效提升小麦植株中下部叶片光合速率,促进茎秆糖类物质合成积累,增强小麦茎秆抗倒伏性能,进而降低小麦倒伏发生率,提高籽粒产量。

不同降雨年型施氮量与收获期对夏玉米产量及氮肥利用效率的影响

为探讨施氮量与收获期对华北平原热量资源限制区夏玉米籽粒灌浆与脱水、产量形成及氮素利用效率的调控效应,本研究采用二因素区组试验设计,因素公顷施氮量为0(N0)、120 kg(N120,2021)、180 kg(N180)、240 kg(N240)、300 kg(N300)、360 kg(N360)和450 kg(N450,2020),因素收获期设为传统收获(normal harvest,NH)和延迟收获(delayed harvest,DH),测定干物质积累量(dry matter accumulation,DM)、籽粒灌浆与脱水、产量(grain yield,GY)及其构成因素、氮肥偏生产力(nitrogen partial factor productivity,PFPN)和农学利用效率(nitrogen agronomic use efficiency,ANUE)。与干旱年型(2020年)相比,丰水年型(2021年)DM和粒重(grain weight,GW)显著下降16.3%~81.5%和2.1%~28.1%,穗粒数(ear grains number,EGN)显著减少44.7%~47.4%,导致GY、PFPN和ANUE显著降低31.4%~58.3%、27.2%~30.0%和2.9%~18.0%。与N0相比,施氮显著提高DM,GW提高14.6~82.1 mg grain^(-1),最大灌浆速率(maximum grain filling rate,G_(max))及其生长量(weight increment of G_(max),W_(max))提高0.2~3.4 mg(grain d)^(-1)和10.4~44.1 mg grain^(-1),到达G_(max)时期(time reaching the G_(max),T_(max))提前0.4~7.0 d,GY显著提高51.5%~169.5%(P<0.01),N240增产效应最优;增施氮肥导致PFPN和ANUE比N180/N120显著降低11.7%~57.9%和2.5%~54.9%、19.9%~52.6%和4.9%~37.0%。与NH相比,DH处理DM和GW显著提高0.8%~55.7%和3.4%~79.3%,籽粒含水率(grain moisture content,GMC)显著降低至22.0%~27.9%,GY、PFPN和ANUE显著提高10.6%~18.5%、4.4%~26.8%和1.5%~48.6%。线性加平台模型分析表明,DH处理比NH GY提高11.3%~12.6%(P<0.01),达12.0×10^(3)kg hm^(-2)和7.0×10^(3)kg hm^(-2),但最优施氮量自200~210 kg hm^(-2)增至247 kg hm^(-2)。综之,华北平原热量限制区夏玉米传统收获情景下减氮至200 kg hm^(-2),产量稳定在6.0×10^(3)~10.5×10^(3)kg hm^(-2)以上;延迟收获情景下,降低籽粒含水率,减氮至240 kg hm^(-2),产量达8.0×10^(3)~12.0×10^(3)kg hm^(-2)以上,PFPN和ANUE最优为19.2~49.6 kg kg^(-1)和15.3~20.8 kg kg^(-1),可为区域夏玉米降低籽粒含水率,实现籽粒机收与减氮稳产高效的生产目标提供理论支撑。

不同降雨年型施氮量对延迟收获夏玉米产量、强弱势粒形态与粒重的影响

【目的】华北平原热量资源有限,夏播玉米收获期籽粒含水率高,影响机械粒收质量,限制了该项技术在该区域的应用。延迟收获条件下,施氮量差异对夏玉米籽粒产量、强弱势粒形态、粒重等关键产量性状的影响尚不明确。通过对不同施氮水平强弱势粒形态、灌浆及脱水过程的系统观测,明确氮肥调控效应,为区域机械粒收夏玉米稳产减氮增效栽培提供支持。【方法】2020—2021年选用粒收夏玉米品种京农科728为材料,采用收获时期和施氮量二因素区组试验设计,收获时期设正常果穗收获(NH)和延迟籽粒收获(DH),6个纯氮施用水平分别为0(N0)、120(N120,2021)、180(N180)、240(N240)、300(N300)、360(N360)和450 kg hm^(-2)(N450,2020),测定产量(GY)、籽粒鲜体积(GFV)、鲜重(GFW)、干重(GDW)、含水率(GMC)及其变化速率。【结果】与干旱年型(2020年)相比,多雨年型(2021年)弱势粒的GFV、GFW和GDW的最大变化速率(Gmax)、生长量(Wmax)和起始势(R0)显著降低,到达最大变化速率时间(Tmax)推迟,活跃期(P)延长,导致弱势粒的GFV、GFW和GDW显著降低15.4%—50.6%、25.4%—62.0%和31.2%—57.3%,而强势粒不显著,GY显著降低3.03×10^(3)—5.44×10^(3)kg·hm^(-2)。多雨年型条件下,弱势粒的GDWGmax、GDWWmax和GDWR0比强势粒显著降低55.1%—258.1%、13.4%—143.0%和12.0%—126.6%,GDWTmax推迟4.2—20.7 d,强势粒的GFV、GFW和GDW比弱势粒显著提高56.8%—69.6%、67.0%—80.4%和54.1%—92.1%。与NH相比,延迟收获籽粒的Gmax和R0提高,强、弱势粒的P显著延长;在干旱年型和多雨年型下,GFV、GFW显著降低2.1%—8.1%和12.2%—17.1%、4.0%—5.2%和15.7%—19.5%,GDW自25.1—28.2 g/100 grains提高到28.0—34.4 g/100 grains,GMC降至22.6%—26.0%,降幅达31.3%—40.4%,产量提高0.02×10^(3)—1.67×10^(3)kg·hm^(-2)。干旱年型施氮水平间的GFV、GFW、GDW无显著差异;多雨年型N240-N360处理的GDWGmax、GDWWmax比N180提高,GDWTmax推迟,GDWP延长,差异均达显著水平,且对弱势粒影响强于强势粒。DH处理下,N240-N360弱势粒的GFV、GFW和GDW比N180显著提高25.7%—85.3%、59.4%—83.6%和17.9%—43.9%。多雨年型下氮肥的增产效应(74.4%—169.5%)显著高于干旱年型(51.5%—99.1%),N240 GY比N120-N180显著提高12.6%—54.5%。【结论】华北平原热量资源限制区小麦-玉米种植制度,将冬小麦变为春小麦,夏玉米延迟收获23—33 d,显著提高弱势粒库容与粒重,籽粒含水率降低至籽粒机收含水率标准,实现周年机械化粒收。优化施氮247.2—248.6 kg·hm^(-2),实现不同降雨年型下产量稳定在7.0×10^(3)—12.0×10^(3)kg·hm^(-2)的稳产减氮增效的生产目标。

模拟降雨量条件下沟垄集雨种植对土壤养分分布及夏玉米根系生长的影响

为了探索沟垄集雨种植的增产机理及其适宜的雨量范围，在人工模拟降雨条件下研究了不同降雨量沟垄集雨种植对夏玉米（ZeaMaysL．）根系性状及土壤速效养分含量的影响。结果表明，沟垄集雨种植处理后，耕层（0~40cm）土壤速效N、P、K和有机质的含量明显增加（P〈0．05）。夏玉米根长、根表面积、根体积和根干重在230mm和340mm降雨量下明显增加，440mm雨量下，分别有所减小（P〈0．05）；籽粒产量增加幅度在230~440mm雨量下随雨量增大而减小（P〈0．05），440mm时增产效果已不明显。可见，沟垄集雨种植协调了土壤水分和养分的关系，在一定雨量下可促进植株根系的发育，其种植玉米适宜的雨量上限可能在全生育期降雨量440mm左右。

半干旱区沟垄集雨对玉米光合特性及产量的影响

在中国西北黄土高原半干旱区,沟垄集雨种植(RFPRH)系统被逐步推行,以改善农田水分状况,提高作物水分利用效率(WUE),达到高产稳产的目的。为了探索该种植方式的适宜降雨量,在人工模拟不同降雨量下,以传统平作为对照,研究了沟垄集雨种植对夏玉米土壤水分含量、功能叶片的光合参数、荧光参数和叶绿素相对含量(SPAD)以及籽粒产量的影响。结果表明,在230mm和340mm降雨量下,集雨处理的净光合速率(Pn)、气孔导度(Gs)、最大荧光(Fm)、可变荧光(Fv)、PSII最大光化学量子产量(Fv/Fm)、PSII的潜在活性(Fv/Fo)和光化学猝灭系数(qP)均较对照显著增加;叶绿素相对含量(SPAD)分别提高17.7%和13.9%,叶片瞬时水分利用效率提高26.9%和10.1%,籽粒产量增加75.4%和36.7%。在440mm降雨量条件下,集雨处理的Fm、Fv/Fm、Fv/Fo、qP和SPAD值在拔节期显著增加,Gs在抽雄期显著增加,Pn在抽雄期和孕穗期显著下降,水分利用效率在全生育期比对照平均低13.2%,其他各生育时期光合生理特性及籽粒产量与对照相比差异不明显。说明沟垄集雨种植在偏旱的年份,可显著提高玉米光合效率和叶片水分利用效率,其全生育期适宜雨量上限可能是440mm。

模拟降雨量下沟垄微型集雨种植玉米的水温效应

【目的】探明沟垄微型集雨种植(垄体覆膜沟内种植)适宜的降雨量范围,为确定合理的微型集雨种植模式提供科学依据。【方法】在夏玉米生长期,人工模拟大、中、小3种降雨量(440、340和230mm),定期测定传统平作(T1)和沟垄微型集雨种植(T2)条件下土壤水分和耕层地温,并分析了农田水分利用效率(water use efficiency,WUE)。【结果】在玉米全生育期230、340和440mm降雨量下,沟垄微型集雨种植农田200cm土层平均储水量分别较平作(平作不起垄不覆膜)增加了2.3%、5.2%和4.5%,耕层0～5cm平均地温分别增加了1.2、1.1和1.0℃。在全生育期230mm和340mm雨量下,WUE较平作分别增加7kg·ha-1·mm-1和3.1kg·ha-1·mm-1,提高了61.24%和26.90%;当全生育期降雨量为440mm时,沟垄微型集雨种植和平作的WUE分别为16.55kg·ha-1·mm-1和17.46kg·ha-1·mm-1,差异不显著。【结论】在夏玉米生育期降雨量为230mm到340mm雨量范围,沟垄微型集雨种植能明显改善玉米的水温条件,提高WUE。

半干旱区模拟降雨下沟垄集雨种植对夏玉米生产影响

在人工模拟降雨条件下研究了不同降雨量沟垄集雨种植对夏玉米(ZeaMaysL.)个体发育、生物量积累及产量的影响。结果表明,沟垄集雨种植处理后,夏玉米生育期提前,株高和叶面积显著增加(p<0.05),在230、340和440mm降雨量下玉米总生物量比平作分别提高44.71%、28.51%和7.58%;230mm和340mm降雨量下,单株籽粒产量比平作分别提高了75.40%和36.70%,穗长分别增加了25.30%和16.00%,穗粒数分别增加了59.30%和29.20%,230mm降雨量下,玉米穗粗和千粒重比平作分别增加了11.40%和10.30%;440mm降雨量下籽粒产量与平作相比差异不明显。

模拟不同雨量下沟垄集雨种植对春玉米生产力的影响

为了探明沟垄集雨种植适宜的降雨量范围,使沟垄集雨系统更加有效,通过大田模拟降雨试验,研究了不同雨量下沟垄集雨种植对农田水温状况及春玉米个体发育、生物量积累、水分利用效率（WUE）和产量的影响。结果表明,在230-440mm雨量下,与平作处理相比,沟垄集雨种植处理后,沟内土壤10cm处温度增加了0.7-1℃,沟内120cm土壤平均储水量增加了5%-12%,玉米的出苗期提前1-2d,生育期普遍提前,株高、功能叶面积和生物量显著增加（P〈0.05）。玉米籽粒产量及WUE在230mm雨量下分别增加了82.8%和77.4%,340mm雨量下分别增加了43.4%和43.1%,440mm雨量下分别增加了11.2%和9.5%。沟垄集雨种植春玉米适宜的雨量上限可能在全生育期降雨量440mm以下。

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。

人工集水面临界产流降雨量确定实验研究

通过在中国科学院寒区旱区环境与工程研究所皋兰生态农业试验站 1 998 1 999年的降雨 -径流观测实验 ,利用直线回归模型确定包括自然集水面在内的 9种人工集水面的临界产流降雨量值 (降雨阀值 )。结果表明 :在不受前期降雨影响下 ,自然黄土坡面、清除杂草自然黄土坡面和粘土夯实集水面的临界产流降雨量分别为 8 5mm ,8 0mm和 4 1mm。在受前期降雨影响下 ,其临界产流降雨量分别为 6 0mm ,5 0mm和 1 9mm。塑料膜、油毡、沥青和混凝土处理集水面的产流过程受降雨量和降雨强度的影响小 ,平均状态下其临界产流降雨量为 0 1～ 1 5mm。塑料膜、油毡、沥青、塑料 +小砾石和塑料 +大砾石集水面的临界产流降雨量分别为 0 1 3mm ,0 2 1mm ,0 1 7mm ,0 98mm和 0 85mm。混凝土集水面在干燥情况下的临界产流降雨量为 1 4 8mm ,在不干燥情况下的临界产流降雨量为 1 1 6mm。

垄沟集雨对干旱半干旱区土壤水热条件及老芒麦产草量的影响

为探索和解决干旱半干旱区多年生牧草持续性生产问题,在坝上农牧交错区对垄沟集雨栽培措施下老芒麦草地的生长状况进行了研究。测定比较了垄沟集雨处理和平作对照的土壤水热条件,地下生物量分布以及不同阶段的产草量。结果表明:垄沟集雨使种植区土壤表层体积含水率幅度增加9.67%～26.94%,生长季土壤表层0～30cm贮水量提高13.38%～24.92%,土壤表层最低温度提高1.02～2.08℃;土壤水热条件的改善增加了表层0～10cm根系的分布,提高产草量98%～230%。垄宽60cm沟宽30cm的处理的产草量最高为5.34t/hm2,2a年平均产量为5.34和2.79t/hm2分别比对照1.62和1.18t/hm2提高了230%和136%。垄沟集雨措施对降雨量较少,分布不均匀的干旱半干旱区的人工草地种植具有明显的稳产增产作用。

垄沟集雨种植对旱作紫花苜蓿生长特性及品质的影响

【目的】垄沟覆膜种植紫花苜蓿(Medicago sativa L.),为年降水量250-350mm的中国西北黄土高原区旱作紫花苜蓿的种植提供理论依据。【方法】试验设置膜垄和土垄集雨处理,垄为集雨区,沟为种植区,研究不同沟垄宽比和覆盖方式对旱作紫花苜蓿生长及其品质的影响,并确定最优的集雨处理。【结果】各指标值反映出,膜垄处理明显优于土垄处理;所有处理中以MR60(覆膜处理,沟垄宽比为60cm﹕60cm)表现最优,出苗率、成苗率和越冬率分别较对照(平作,CK)提高16.01%、16.03%和18.25%,生长速度和再生速度分别较CK提高65.30%、56.41%,生长高度、分枝数和干草产量分别较CK提高65.12%、29.04%和238.20%,茎叶比较CK降低22.45%,粗蛋白(crude protein,CP)和粗脂肪(crude extract,EE)含量分别较CK提高29.82%、9.31%,粗灰分(crude ash,CA)含量较CK降低14.54%,粗纤维(crude fiber,CF)含量与CK差异不显著。【结论】在试验地区及其相似地区采用垄覆膜沟覆秸秆集雨种植紫花苜蓿,可以促进苜蓿出苗和成苗,提高苜蓿越冬率,促进苜蓿生长,显著提高苜蓿干草产量的同时有效改善干草的品质,最终实现高产、优质的双重目标。

垄覆膜集雨种植对二年龄苜蓿草地土壤养分的影响

旱作条件下,垄覆膜集雨措施应用于紫花苜蓿种植,垄为集雨区,沟为种植区,研究不同沟垄宽比和覆膜方式对2年龄苜蓿草地土壤养分影响。结果表明,垄覆膜种植苜蓿第2年返青前、第2茬刈割后,各处理0～20,20～40cm土壤全磷(TP)含量均无显著差异,膜垄、土垄处理0～20,20～40cm土壤有机质(SOM)、全氮(TN)含量均随着垄宽度的增大而增加,且膜垄处理0～40cm土层SOM、TN、速效氮(AN)、速效磷(AP)、缓效钾(SAK)、速效钾(AK)含量均显著高于土垄处理及CK(平作),所有处理中MR60、MR75土壤养分含量最高。刈割后和返青前相比,膜垄处理0～40cm土层SOM的减少量显著低于土垄处理,膜垄处理0～40cm土层TN的增加量及AN、AP、SAK、AK的减少量均显著大于土垄处理;相关性分析表明,各处理0～40cm土层SOM的减少量与苜蓿的经济产量呈显著的负相关,0～40cm土层TN的增加量、AP的减少量、AK的减少量均与苜蓿的经济产量呈显著的正相关。说明垄覆膜集雨种植紫花苜蓿能够有效的抑制SOM含量的降低,且膜垄的抑制作用大于土垄,同时促进TN含量的增加,有效地提高0～40cm土壤养分,有利于土壤的可持续利用。

人工集水面降雨径流观测实验研究

野外降雨径流观测实验研究表明 :土质集水面 (自然黄土坡面、清除杂草自然黄土坡面和夯实集水面 )的降雨产流方式为超渗产流 ,受降雨强度的影响大 ,径流的产生主要是由几次高强度的暴雨引起。此类集水面的年平均集水效率在 7.4%～ 35 .5 %之间 ,因此 ,增大集水区面积是保证土质集水面收集到更多雨水的基本途径。油毡、沥青和混凝土处理集水面的产流过程受降雨量和降雨强度的影响小 ,年平均集水效率在 5 0 %～ 80 %之间 ,但投资成本较高 ,其雨水利用方向是和设施农业相结合 ,修建固定集水面 ,发展高投入高产出农业。塑料膜集水面一次性投入低且平均集水效率较高 ,但寿命较短 ,建议利用简单临时性的移动塑料集水面收集雨水以供大田作物缺水期补灌。