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1.
黑土区垄作方式对坡耕地土壤侵蚀的调控效果 总被引：1，自引：0，他引：1
[目的]分析黑土区不同垄作方式对坡耕地土壤侵蚀的调控效果,为该区土壤侵蚀防治提供科学指导。[方法]在5°和10°坡耕地开展人工模拟降雨试验,降雨强度为50,100 mm/h,垄作方式包括：横坡垄作、垄向区田、顺垄+底部横垄和横垄+排水沟,对照处理为传统顺坡垄作。[结果]试验条件下,与顺坡垄作处理相比,横坡垄作、垄向区田、顺垄+底部横垄和横垄+排水沟处理均可有效调节径流、降低土壤侵蚀量,但不同垄作方式对径流和侵蚀的调控效果随着降雨强度和坡度的增加而减小。在5°坡耕地,横坡垄作方式对径流和侵蚀的调控效果最佳,产流率和土壤侵蚀速率分别稳定在15.0 mm/h和0.2 kg/(m~2·h)以下。在50,100 mm/h降雨强度下,与顺坡垄作处理相比,其径流量分别降低92.3%和83.9%,土壤侵蚀量分别降低96.8%和94.6%;而垄向区田方式对径流和侵蚀的调控效果略大于顺垄+底部横垄处理。在10°坡耕地,横坡垄作方式在降雨前期具有较好的蓄水保土作用,但在降雨后期垄体易损坏,造成土壤侵蚀量剧增;横垄+排水沟方式在降雨前期能够蓄水保土,在降雨后期能够较好地进行排水。[结论]在坡度平缓的坡耕地,应... 相似文献
2.
降雨侵蚀因子和植被类型及覆盖度对坡耕地土壤侵蚀的影响 总被引：17，自引：4，他引：13
为探讨降雨和植被对辽西褐土区农耕坡地土壤侵蚀的影响,2006-2010年采用坡面径流小区观测法研究了天然降雨条件下降雨侵蚀因子、植被覆盖度、植被类型对坡耕地地表径流量、土壤侵蚀量的影响。设5°和10°两个坡度水平,以甘薯和谷子为供试作物,2006-2007年对照区为天然荒草地,2008-2010年为裸坡地。结果表明,甘薯地径流量和侵蚀量与降雨量(R)、最大30 min雨强(I_(30))、R×I(平均雨强)、R×I_(30)正相关显著(P0.05);裸坡地径流量与R、R×I_(30)正相关显著(P0.05),侵蚀量与I_(30)、R×I_(30)正相关显著(P0.05),与降雨量相关不显著(P0.05)。甘薯地和裸坡地的径流量和侵蚀量与平均降雨强度正相关均不显著(P0.05)。回归分析表明,降雨量主要影响径流量,最大30 min雨强主要影响侵蚀量。中、高雨强下,侵蚀量与径流量显著正相关(P0.01)。甘薯地径流量和侵蚀量与植被覆盖度呈显著负指数关系(P0.05)。5°坡耕地,不同植被类型侵蚀量为甘薯地荒草地谷子地;10°坡耕地,荒草地侵蚀量总体最少。多元回归分析表明,对土壤侵蚀的影响为地表径流降雨侵蚀力(R×I_(30))植被覆盖度。通过连续5 a坡面径流小区观测,初步探明降雨和植被对辽西褐土区农耕坡地土壤侵蚀的影响,可为该区坡耕地土壤侵蚀的有效防治提供一定的理论依据和技术支撑。 相似文献
3.
不同利用方式红壤坡地土壤水分分配及水肥流失研究 总被引：1，自引：0，他引：1
研究南方红壤坡地3种典型利用方式（休闲荒地、常规农作和茶园）的土壤水分分布特征及水肥流失情况。结果表明:①不同土地利用方式下的土壤水分含量变化与降雨量变化密切相关,土壤水分含量高低顺序为休闲荒地>茶园>常规农作。②常规农作产流不稳定,产流量明显高于休闲荒地和茶园,休闲荒地和茶园的产流无差异。③随径流损失的养分以氮素损失为主,养分损失量高低顺序为:常规农作>茶园>休闲荒地。从涵养水源、水土保持及经济效益综合考虑,南方红壤坡地利用以茶园利用为宜。 相似文献
4.
F.L. Engel I. Bertol S.R. Ritter A. Paz Gonzlez J. Paz-Ferreiro E. Vidal Vzquez 《Soil & Tillage Research》2009,103(2):216
Soil tillage may increase vulnerability to water erosion, whereas no tillage and other conservation cultivation techniques are viewed as strategies to control soil erosion. The objective of this research was to quantify runoff and soil losses by water erosion under different soil tillage systems at the Santa Catarina Highlands, southern Brazil. A field study was carried out using a rotating-boom rainfall simulator with 64 mm h−1 rainfall intensity on a Typic Hapludox, between April 2003 and May 2004. Five rainfall tests were applied along successive cropstages. Surface cover was none (fallow) or soybean (Glycine max, L.). Five treatments were investigated, replicated twice. These treatments were conventional tillage on bare soil (BS) as a control treatment and the following treatments under soybean: conventional tillage (CT), no tillage over burnt crop residues on never before cultivated land (NT-B), no tillage over desiccated crop residues, also on never before cultivated land (NT-D) and traditional no tillage over desiccated crop residues on a soil tilled 4 years before this experiment (NT-PT). Water losses by surface runoff seemed to be more influenced by vegetative crop stadium than by tillage system and consequently a wide range of variation in surface runoff was found, following successive cropstages. The most efficient tillage system in reducing surface runoff and soil losses was no tillage, particularly the NT-PT treatment. Sediment losses were more influenced by tillage system than water losses. In the NT-B, NT-D and NT-PT treatments the rate of sediment losses along the crop vegetative cycle showed a tendency to increase from the first to the second cropstages and later to decrease from the third cropstage onwards. In the conventionally tilled treatment (CT) soil losses were greater than in any of the no tillage treatments (NT-D, NT-B and NT-PT) during the initial growth periods, but at the end of the vegetative period differences in sediment rates between tilled and non-tilled treatments tended to be smaller. In the BS control treatment, soil losses progressively increased following the vegetative growth season of soybean. 相似文献
5.
P. A. Lawrence B. J. Radford G. A. Thomas D. P. Sinclair A. J. Key 《Soil & Tillage Research》1994,28(3-4):347-364
Sodosol soils are at risk of degradation under existing fallow management practices involving tillage. Topsoil erosion exposes horizons with reduced infiltration and low concentrations of plant nutrients. Conservation management systems are needed on these soils to avoid a reversion to low intensity grazing. This paper reports on a 4 year study (1986–1989) of the effects of tillage practices on profile soil water and crop yield in a Sodosol (Typic Natrustalf) in central Queensland, Australia. The tillage treatments were: zero till fallow (weed control by herbicides), reduced till fallow (chisel plough/scarifier or herbicides) and conventional till fallow (chisel plough/scarifier) in two linked experiments. In the first experiment, wheat was grown in three contour bays (approximately 1 ha), and in the second, wheat was grown in replicated plots (30 m × 6 m) to allow statistical comparisons.
Zero till provided consistent advantages in grain yield in all 4 years compared with conventional till. Zero till also outyielded reduced till as well as conventional till in the plot experiment. The average yield increase of 0.5 t ha−1 in zero till compared with convention till was associated with greater water use and increased water use efficiency. Tillage practice caused only marginal differences in the available water content in the root zone (0–100 cm) at sowing; zero and reduced till contained, on average, an additional 4 and 8 mm, respectively, compared with conventional till. The tillage treatments had no effect on plant available water capacity. Some of the soil water that accumulated during the fallow drained beyond the root zone in all treatments and was not available to the following wheat crop. At the conclusion of the experiment, soil water accumulation in the 100–180 cm soil layer was 86 mm in zero till, 39 mm in reduced till and 40 mm in conventional till.
Results indicate that zero till can be a more productive wheat farming practice than conventional mechanical tillage. The increase in water storage below the root zone of the wheat crop shows that there may be benefit in using a deeper-rooting crop or pasture species in rotation with wheat, particularly after zero till fallows. 相似文献
6.
为有效防治坡耕地水土流失,持续利用坡耕地,于2007-2010年在黄土高原西部坡耕地上研究保护性耕作对水土流失的影响,重点探讨传统耕作与免耕秸秆覆盖2种耕作措施下春小麦、鹰嘴豆、马铃薯与紫花苜蓿间作的水土流失规律。结果表明:(1)各处理8月份的径流量分别占观测时段内总径流量的46.46%～51.29%,侵蚀量分别占观测时段内总侵蚀量的40.10%～61.22%。(2)降雨量与径流量、侵蚀量间呈现多元多项式关系。(3)2007-2010年不同种植模式下径流总量和侵蚀总量的变化趋势是一致的,均表现出NTSPL相似文献
7.
黑土坡耕地不同水土保持措施的土壤水蚀特征研究 总被引：2，自引：1，他引：1
针对北方干旱地区坡耕地严重的水土流失问题,采取垄向区田、深松、横坡种植、免耕播种等水土保持耕作措施,于2010年,以黑龙江省齐齐哈尔市东兴村5°坡耕地径流场为研究对象,研究了不同耕作措施对地表径流、土壤侵蚀和降雨入渗的影响。结果表明,这几种水土保持耕作措施均有不同程度的减流减沙作用,其中横坡种植效果最为明显,地表径流量和土壤流失量较常规耕作分别减少了92%和90%,稳定入渗率较常规耕作提高了41.2%。不同耕作措施的径流系数过程线的变化、径流含沙率变化以及产流量、产沙量的变化均符合横坡免耕>横坡种植>深松+区田>垄向区田>少耕深松>免耕>常规耕作>裸地这一变化规律。 相似文献
8.
作物覆盖度对土壤侵蚀的影响 总被引：1，自引：0，他引：1
为研究传统耕作模式下坡耕地作物覆盖度对土壤侵蚀的影响,利用冬小麦不同的种植密度和生长期来模拟作物不同的覆盖度情况。采用人工模拟降雨方法测定0,150万,250万,350万,450万株/hm2 5种不同密度处理在不同生育期的覆盖度、地表径流和土壤侵蚀,分析作物覆盖度对土壤侵蚀的影响。结果表明:(1)坡耕地作物种植密度的不同导致覆盖度产生差异,对土壤侵蚀有明显的影响,作物覆盖度一般随种植密度的增加而增加,但如果密度过大,由于生长状况不佳,覆盖度反而变小,表现为7.5万株/hm2时覆盖度最大,种植密度最大的9万株/hm2的覆盖度却不是最大;(2)侵蚀量和径流量与作物覆盖均呈较好的指数函数关系,分别为Y=44.37e-0.09x(p＜0.01),Y=1089.19e-0.02x(p＜0.01),即随作物覆盖度的增加,径流量和侵蚀量减少;(3)土壤侵蚀和地表径流之间存在显著的指数函数关系(R2=0.96)。研究结果对分析传统耕作农地的土壤侵蚀,量化耕作措施因子和准确预测土壤侵蚀,指导农田水土保持有重要意义。 相似文献
9.
土壤侵蚀对坡耕地耕层质量退化作用及其评价趋势展望 总被引：11，自引：8，他引：3
土壤侵蚀是导致坡耕地耕层质量退化和土壤生产力不稳定的关键驱动因素。该文从水蚀区坡耕地侵蚀控制和生产功能角度,在解析地块尺度土壤侵蚀、水土保持、农业活动对坡耕地耕层生态过程作用特征的基础上,系统分析了土壤侵蚀对坡耕地耕层质量退化作用、影响效应及作用途径。认为:1)坡耕地耕层质量变化由降雨侵蚀、耕作活动交互作用的生态过程决定,2种作用的时间、空间尺度不同;耕层土壤参数在坡耕地农业生产中作用分为保水、保土、保肥和增产潜力,由地块尺度农作物-耕层耦合效应决定土壤生产能力、坡耕地水土流失特征及耕层侵蚀性退化方向及程度。2)土壤侵蚀对坡耕地耕层质量退化作用表现为土壤性质恶化、土壤质量劣化、土地生产力衰退3个方面,耕层土壤物理性质变异程度大于化学性质变异,径流作用导致的土地生产力衰退大于土壤流失作用。3)坡耕地耕层质量评价指标体系应兼顾侵蚀下降、产量提升2个目标,地块尺度诊断指标有效土层厚度、耕层厚度、土壤容重、土壤抗剪强度、土壤有机质、土壤渗透性可作为合理耕层评价最小数据集;坡耕地合理耕层适宜性分为5级,其诊断指标分级标准宜与土壤侵蚀分级和耕地地力分级衔接。4)坡耕地合理耕层评价未来应密切关注耕层质量诊断指标最小数据集、坡耕地合理耕层阈值/适宜值分级标准、坡耕地水土流失阻控标准拟定3个主要方向。研究可为深入认识坡耕地侵蚀性退化机制,辨识坡耕地合理耕层调控途径以及坡耕地合理耕层构建技术参数提供依据。 相似文献
10.
Y.X. Li J.N. Tullberg D.M. Freebairn N.B. McLaughlin H.W. Li 《Soil & Tillage Research》2008,100(1-2):25-33
Soil water conservation is critical to long-term crop production in dryland cropping areas in Northeast Australia. Many field studies have shown the benefits of controlled traffic and zero tillage in terms of runoff and soil erosion reduction, soil moisture retention and crop yield improvement. However, there is lack of understanding of the long-term effect of the combination of controlled traffic and zero tillage practices, as compared with other tillage and traffic management practices.In this study, a modeling approach was used to estimate the long-term effect of tillage, traffic, crop rotation and type, and soil management practices in a heavy clay soil. The PERFECT soil–crop simulation model was calibrated with data from a 5-year field experiment in Northeast Australia in terms of runoff, available soil water and crop yield; the procedure and outcomes of this calibration were given in a previous contribution. Three cropping systems with different tillage and traffic treatments were simulated with the model over a 44-year-period using archived weather data.Results showed higher runoff, and lower soil moisture and crop production with conventional tillage and accompanying field traffic than with controlled traffic and zero tillage. The effect of traffic is greater than the effect of tillage over the long-term. The best traffic, tillage and crop management system was controlled traffic zero tillage in a high crop intensity rotation, and the worst was conventional traffic and stubble mulch with continuous wheat. Increased water infiltration and reduced runoff under controlled traffic resulted in more available soil water and higher crop yield under opportunity cropping systems. 相似文献
11.
三峡库区坡耕地不同施肥水平与耕作模式径流泥沙流失规律 总被引：1，自引：0，他引：1
为有效防治坡地水土流失,减轻农业面源污染,以原位径流小区长期（2010—2012年）观测试验为基础,以“冬小麦—夏玉米”种植模式为研究对象,设置对照（T0）、常规（T1）、优化（T2）、增量（T3）、横坡垄作（T4）5个处理,分析了三峡库区紫色土坡耕地不同施肥水平与耕作模式下径流泥沙流失规律及其对降雨的响应。研究发现:（1） 各处理5月份的径流量占观测时段内总径流量的16.39%～21.96%,侵蚀量占观测时段内总侵蚀量的12.53%～25.56%,产生侵蚀性降雨的最小降雨量为20.5 mm。（2） 不同施肥与耕作模式下降雨量与径流量、侵蚀量均呈y=ax+b（a > 0）的线性关系;通径分析表明,侵蚀量的变化是径流量直接作用的结果,施肥对土壤侵蚀及产流的影响是通过改变土壤理化性质和作物地面覆盖度而实现的。（3） 不同施肥水平与耕作模式下径流总量与侵蚀总量的变化趋势一致,在不同施肥水平下径流总量与侵蚀总量均表现出:T0 > T1 > T3 > T2,不同耕作模式下径流总量与侵蚀总量均表现出:T2 > T4。横坡耕作和优化施肥模式能够更有效地减少地表径流,降低土壤侵蚀量,是三峡库区防治坡耕地水土流失的有效途径。 相似文献
12.
翻耕对花岗岩坡地水分转化及产流产沙特征影响研究 总被引：5，自引：0，他引：5
坡地水土流失是导致土壤质量退化与土地生产力下降的重要原因。采用人工降雨野外模拟试验方法研究了翻耕前后花岗岩坡地水分转化及产流产沙特征的影响。研究表明,翻耕可以提高水分转化率,但从总趋势上看,翻耕条件下径流含沙量与产流产沙量均显著高于翻耕前,其中平均含沙量增加1.5倍,产沙量增加12%,故应多种耕作措施有机结合;降雨过程中,随着产流时间的延长,坡地产沙量呈加速增加的趋势,而且增加速度显著快于坡面径流。因此采取适当措施延长初始产流时间,减少产流量以及提高降雨向土壤水分的转化率均可有效减少坡地土壤流失量。 相似文献
13.
耕作措施及雨强对南方红壤坡耕地侵蚀的影响 总被引：7，自引：3，他引：4
选择典型南方红壤区平均坡度为10°的坡耕地小区进行天然降雨观测,对横坡耕作、顺坡耕作、顺坡耕作+植物篱、稻草覆盖4种耕作措施在侵蚀过程中的径流泥沙和养分流失特征进行研究。结果表明,监测期间,径流深和泥沙流失量基本随雨强的增大而增加。随着耕作措施由顺坡耕作向顺坡耕作+植物篱、横坡耕作、稻草覆盖的转换,减流效益、减氮效益和减磷效益依次增大。稻草覆盖措施减流效益最佳,为91.77%;横坡耕作措施减沙效益最佳,为98.91%;稻草覆盖、横坡耕作和植物篱3种措施在防治高强度降雨引发的土壤侵蚀和养分流失具有较高的效益。耕作措施对泥沙粒径分布有影响。与顺坡耕作、横坡耕作相比,植物篱和稻草覆盖措施能够更有效地拦截径流中的粗颗粒。该研究可为南方红壤丘陵区坡耕地选择合适的耕作措施和防治农业非点源污染提供依据。 相似文献
14.
ABSTRACTSoil erosion and rainfall-induced runoff are well studied yet remain somewhat unpredictable from one natural rainfall to the next, due to interactions between erosion parameters. This study quantified the relationship between annual (2011–2016) and individual (2016) rain events with overland flow (runoff) and soil loss in China’s northern ‘corn-belt’. Two tillage practices and slopes were evaluated (no-till and conventional till, 5° and 7° slopes). Results showed 54 rainfall events for a total of 394 mm precipitation ranging between May and October 2016. Runoff occurred 13 times in the conventional till with 7° slope, accounting for 25.9% of the precipitation volume and caused 15.6 t ha?1 erosion. It occurred twice in the no-till with 5° slope plot and caused 0.2 t ha?1 erosion., Thus the no-till with 5° slope treatment is the best tillage system to protect soil in Mollisols in Northeast China. Broad analysis coupled with a detail review of three rainfall events demonstrates that water either runs off plots quickly or rapidly infiltrates while sediment moves in a pulsing manner. 相似文献
15.
为探究黑土区坡耕地垄侧少耕措施对土壤侵蚀特征的影响,在5°和7°坡面开展人工模拟降雨试验,降雨强度为75,100 mm/h,横垄处理方式包括全松（土壤容重均为1.00 g/cm3）、上松下实（土壤容重分别为1.00,1.20 g/cm3）、上实下松（土壤容重分别为1.20,1.00 g/cm3）及全实（土壤容重均为1.20 g/cm3）4种。结果表明：垄侧少耕措施有助于延缓横垄溢流时间,具有明显的调控土壤侵蚀作用。土壤侵蚀量大小总体表现为全松>上松下实>全实>上实下松。除75 mm/h降雨强度下的5°坡面外,与全松处理相比,上实下松和全实处理的径流量分别减少16.1%~19.4%和6.6%~11.4%,土壤侵蚀量分别减少25.0%~52.5%和17.9%~31.6%,且上实下松和全实处理的径流率和土壤侵蚀速率随降雨历时的变化相对比较平稳。可见,垄侧少耕措施在调控总径流量和土壤侵蚀量的同时,也具有较好地调控径流侵蚀过程的作用。因此,建议根据黑土区坡耕地具体降雨特征和地形坡度等因素科学选用垄侧少耕措施。 相似文献
16.
凌源市推广“金字塔”模式开发治理成效显著 总被引：2，自引：0，他引：2
《中国水土保持》1996,(2):38-41
凌源市推广“金字塔”模式开发治理成效显著刘海潮，张凤山，祁放（辽宁省凌源市水利局，１２２５００）凌源市水土保持小流域综合治理，经过多年的不断完善、总结、提高，形成了一林戴帽，二林围顶，果牧拦腰，两回穿靴，一龙坐底的产金字塔＂综合治理模式ＪＩ９８８年经... 相似文献
17.
Field and laboratory experiments were conducted on a crusting loess soil in the northern Negev (Israel) with the aim of improving the efficiency of the use of rain by row crops, either in dryland or irrigated farming, and to decrease erosion. The specific objective of the experiments described was to develop methods that enhance infiltration of rainfall during the winter fallow season in an area with a mean annual rainfall of 400 mm which is subject to wide variation.It was found that the traditional tillage system consisting of deep ploughing (35–45 cm) of dry soil in the fall followed by disking, smoothing and ridging is the worst choise as it could result in runoff losses of as much as 60% of the rainfall, accompanied by accelerated erosion. This water loss can be critical to the success of dryland cotton and also determines whether or not a pre-irrigation of about 25% of the total annual water allotment must be given to irrigated cotton.The traditional practice was compared with: deep ploughed land left fallow during the entire rainy season; ridging after subsoiling instead of deep ploughing; subsoiling and ridging carried out in one minimum tillage operation; direct ridging without primary tillage and basin tillage of ridges following either deep ploughing, subsoiling or minimum tillage.This study showed that by far the most effective method for enhancing infiltration and eliminating runoff was the basin tillage system. The method is adaptable both to mechanized farming and to farming based on animal power or manual labour, and its application can ensure success where rainfall is limiting.It was found that laboratory characterization of soil hydraulic properties with a static rainfall simulator allows prediction of runoff on crusting soils. This means that the need for, and the effectiveness of, conservation measures may be estimated using disturbed soil samples, which is quicker and cheaper than field tests. 相似文献
18.
等高耕作对不同坡度坡面土壤侵蚀过程的影响 总被引：1，自引：0，他引：1
等高耕作是一种典型的农业耕作措施,通过影响坡面填洼、入渗等进而影响坡耕地坡面土壤侵蚀过程。通过人工模拟降雨试验,设计降雨强度(90 mm/h)、5个地表坡度(3°,5°,10°,15°,20°)以及2种坡面处理(等高耕作和平整坡面),对径流强度、侵蚀率、径流含沙量、减流减沙效益等指标进行综合对比分析,与平整坡面进行比较,探究了黄土高原坡耕地等高耕作措施对坡面土壤侵蚀过程的影响。结果表明：(1)与平整坡面相比,等高耕作明显延缓坡面初始产流时间,使初始产流时间延迟11.58～31.91 min,随着坡度增大,等高耕作初始产流时间延长效应逐渐减弱。(2)等高耕作具有削弱径流强度和侵蚀率的作用,与平整坡面相比,等高耕作的坡面径流强度、侵蚀率和径流含沙量分别减少11.77%～94.92%,20.69%～99.27%和2.46%～88.40%。但等高耕作减少产流产沙能力有限,若坡面发生断垄,等高耕作坡面的径流强度、侵蚀率、径流含沙量都可能接近或大于平整坡面。(3)在降雨过程中,累计产沙量与累计径流量之间满足线性正相关关系,等高耕作累计产沙量随累计径流量的增大幅度始终小于平整坡面。(4)等高耕作在不... 相似文献
19.
红壤丘陵区坡长对作物覆盖坡耕地土壤侵蚀的影响 总被引：6，自引：2，他引：4
坡长对坡耕地土壤侵蚀的影响随雨强的不同而变化,为解决南方红壤丘陵区坡耕地水土流失问题,该文采用野外人工模拟降雨的方法,研究了南方红壤丘陵区作物覆盖坡耕地上不同雨强下坡长对其土壤侵蚀的影响,并探讨了侵蚀增强的临界雨强和设置水土保持措施的合理坡长,结果表明:产沙量随坡长延长整体呈增大趋势,但存在一定的波动,二者的关系可用幂函数(决定系数0.84)表示。坡长延长相同长度时,产沙量不呈比例增加,但每隔4 m产沙量增量有减少的趋势,且径流侵蚀产生的泥沙中主要为粒径0.002~0.02 mm的粉粒及粒径0.002 mm的黏粒,加剧了耕地土壤粗化,因此,可每隔4 m设置水土保持措施,有效减少坡耕地水土流失。坡面径流侵蚀产沙量随着雨强的增大而增加,坡长越长,产沙量随雨强增加速度越快,二者呈幂函数关系(决定系数0.76),60 mm/h是红壤丘陵区侵蚀增强的临界雨强;雨强、坡长与产沙量均呈正相关关系,且雨强对坡耕地产沙量的影响较坡长大。对不同雨强下坡长对作物覆盖坡耕地土壤侵蚀的影响研究,可以为南方红壤丘陵区坡耕地水土流失的治理提供一定的理论依据。 相似文献
20.
In the northern Negev of Israel, a typical semi-arid region with a Mediterranean rainfall pattern, wheat production is limited mainly by the amount of available water. Despite the common occurrence of drought years, storm runoff coefficients for unit areas may reach 30–50% of rainfall. Runoff is the main cause of serious erosion damage consisting of soil loss, gully development and loss of productivity.The system of tied ridges or basin tillage, which effectively eliminated over 90% of runoff and erosion in fallow fields before cotton, appears to be a promising solution to the problem of both soil and water conservation in drilled crops as well. Analysis of the long-term rainfall record of the region and the predicted runoff indicates that the basin-tillage system can decrease runoff by at least 50% as compared with the conventional planting system. Experiments carried out during the 1980–1981 rainy season proved that even in a relatively dry year the basin tillage system was effective in increasing wheat yield by about 50% and eliminating erosion. 相似文献