基于不同农作物措施的产流产沙特性分析

根据大石桥市刘家沟流域2018—2020年不同农作物覆盖下的产流产沙量观测数据以及自然降雨数据,研究分析不同雨型不同农作物条件下15°棕壤坡面产流产沙特性。结果表明:①不同场次降雨中玉米措施的土壤流失量及产流量较大,谷子与红薯措施较小,大豆与花生措施相近;②降雨量、I_(30)均与不同农作物小区产流产沙量呈极显著和显著相关性;③参照I_(30)、降雨历时及降雨量将侵蚀性降雨划分成3种类型,不同雨型下的5种作物小区产流产沙特性存在明显差异,各作物措施在Ⅲ雨型条件下的土壤流失量及产流量最大,红薯土壤流失量及产流量在不同雨型下均最小,红薯与其它农作物相比具有更好的水土流失防治效果。

降雨对江子河小流域不同农作物措施坡面产流产沙的影响

水土流失已成为我国主要的生态环境问题之一。基于安徽大别山区江子河小流域2012—2019年自然降雨径流泥沙观测资料,探讨雨型对不同农作物措施坡面产流产沙的影响,采用随机森林算法分析降雨因子与水沙之间的关系。结果表明,在不同场次降雨中,径流量、土壤流失量随降雨场次变化规律较一致,红薯措施产流量及土壤流失量较大,茶叶措施最小。降雨分为3类:A型降雨(低频率、长历时、大雨量、高雨强)、B型降雨(高频率、短历时、小雨量、低雨强)、C型降雨(较低频率、较长历时、中等雨量、较高雨强),对产流产沙的影响表现为A型>C型>B型。降雨量对产流的影响程度最高,土壤流失量受PI、PI 60及降雨量和I 30的影响,I 60对产流产沙的影响程度偏低,小于11%。各农作物措施小区的径流深和土壤流失量相关性显著且具有线性关系,土壤流失量的增速为红薯>桑树>茶叶>板栗>黄豆>油茶。研究结果可为坡面侵蚀预报模型的建立提供重要的理论依据,对安徽大别山区水土保持工作的开展和生态文明建设具有重要的理论价值和实践意义。

大牛岭科技示范园区不同作物措施坡面产流产沙分析

以大牛岭科技示范园区2013-2020年自然降雨径流泥沙观测数据为依据,利用随机森林算法分析了不同作物措施坡面产流产沙特征以及水沙与降雨因子之间的关系。结果显示,土壤流失量、径流量随不同场次降雨的变化规律基本相同,红薯措施的土壤流失量及产流量最小,花生措施较大;A型降雨对产流产沙的影响最大,其次为C型,B型降雨影响最小;I30、PI60、PI、降雨量对土壤流失量产生影响,产流产沙受I60的影响偏低,产流受降雨量的影响最高;土壤流失量与径流深存在显著线性相关性,土壤流失量增速为白蜡树<大豆<李子树<红薯<核桃树<花生。研究成果可为辽阳地区生态文明建设、水土保持规划和低山丘陵区坡面侵蚀预测提供科学指导。

地膜覆盖技术在粮油作物中的应用研究

地膜覆盖技术最早于二十世纪引入我国,是一种能够有效保证作物高产和稳产的措施,因为具有着保墒增墒、保温增光、抑制杂草和改善非生物环境等特点,在粮油作物和经济作物中都有着广泛地运用和推广,是我国农业结构中得创新性和实用性的技术。本文从地膜覆盖技术的原理出发,进而研究出地膜覆盖技术在粮油作物中的应用优化措施。

关于无公害栽培管理技术在农作物种植中的应用

在当前种植业发展过程中,大部分农业栽培技术的使用都是为增加粮食作物的品质和产量,从而有效增强粮食作物的市场竞争力,以达到更高的市场占有率目标。当前,无公害栽培技术在农作物的栽培中已经有了一定范围的应用。在粮食作物栽培技术中,无公害化栽培技术能够更良好地达到上述目标,并可以适应人类对绿色健康食品的需求。

Effects of Different Agricultural Managements on Characteristics of Soil Microbial Community under Continuous Cropped Strawberry(Fragaria ananassa Duchesne)

[Objective] The objective of this study was to investigate the effects of different agricultural managements on soil microbial population,activity,functional diversity and soil enzyme activity in continuous mono-cropping field of strawberry.[Method]A field plot experiment was carried out to evaluate characteristics of soil microbial community by soil enzyme analysis,microbial cultivation and Biolog analysis.[Result]The results showed that bacteria population proportion,the ration of bacteria to fungi,microorganism amount,AWCD,soil dehydrogenase activity,the Shannon,Simpson,and Mcintosh indices of soil microbial communities were obviously increased under strawberry-rice rotation,soil solarization with rice bran,and calcium cyanamide（CaCN2）treatments,in addition,soil urease activity was significantly increased under strawberry-rice rotation and soil solarization with rice bran treatment,when compared with no fertilization.When compared with conventional fertilization treatment,strawberry-rice rotation and soil solarization with rice bran both significantly increased AWCD and Mcintosh index of soil microbial communities,meanwhile respectively increased soil urease and dehydrogenase activity.PCA analyses suggested that carbon utilization of soil microbial communities under strawberry-rice rotation,soil solarization with rice bran,and calcium cyanamide treatment was obviously different from that of conventional fertilization and no fertilization treatment.[Conclusion] strawberry-rice rotation and soil solarization with rice bran were effective agricultural managements to control soil biological degradation under Continuous Cropped Strawberry.

Bioremediation potential of spirulina:toxicity and biosorption studies of lead

This study examines the possibility of using live spirulina to biologically remove aqueous lead of low concentration (below 50 mg/L) from wastewater. The spirulina cells were first immersed for seven days in five wastewater samples containing lead of different concentrations, and the growth rate was determined by light at wavelength of 560 nm. The 72 h-EC50 (72 h medium effective concentration) was estimated to be 11.46 mg/L (lead). Afterwards, the lead adsorption by live spirulina cells was conducted. It was observed that at the initial stage (0–12 min) the adsorption rate was so rapid that 74% of the metal was bio- logically adsorbed. The maximum biosorption capacity of live spirulina was estimated to be 0.62 mg lead per 105 alga cells.

Effects of Contour Hedgerow Intercropping on Nutrient Losses from the Sloping Farmland in the Three Gorges Area,China

Eutrophication is recognized as one of the major environmental problems in the Three Gorges Reservoir.Contour hedgerows have been used as a major soil and water conservation measure in this area.Accordingly,a two-year study was conducted to investigate the effects of contour hedgerow intercropping on nutrient loss from sloping farmland in this area.Four treatments were applied:(1) Maize + Soybean,(2) Maize,(3) Maize + Alfalfa,and(4) Maize + Hemerocallis citrina Baroni.Results indicated that nutrient loss in the control treatment(Maize) was serious,especially the average loss flux of total nitrogen(2245.8 mg) and total phosphate(2434.2 mg) in a typical rainfall event.However,the nutrient losses by runoff in the other three treatments with contour hedgerow intercropping showed significant reduction.Compared with the control treatment,the total nitrogen loss in the Alfalfa and Hemerocallis citrina Baroni decreased by 80.9% and 85.0%,respectively,and the total phosphorus loss in the two treatments decreased by 91.2% and 92.5%,respectively.Therefore,it is concluded that nutrient losses could be reduced by using contour hedgerows in the Three Gorges Region.Reducing runoff volume and sediment loss was the main mechanisms of contour hedgerow intercropping to reduce nutrient loss.

Human-Wildlife Conflicts in Paschim Kusaha Village of Koshi Tappu Wildlife Reserve, Sunsari District, Nepal

Human-wildlife conflict has been one of the most trouble-causing issues in many areas of Nepal including Eastern Nepal. This study assessed the human-wildlife conflict status in Paschim Kusaha Village of Koshi Tappu Wildlife Reserve(KTWR), Sunsari District, Nepal. Data were collected from 47 respondents of different households through questionnaire surveys and formal and informal interviews. Results revealed that the most destructive wild animals were wild elephants, wild boar,and wild water buffalo and the most raided crops were paddy(63.83 %), maize(19.15%), and potato(17.02%). Most of the encounters between humans and wildlife were recorded at night(after dusk and before dawn)(78.72%). Local people were suffering from damage of physical properties, human harassment or nuisance, and depredation of cropland due to wild animals.A total of 70% of respondents had a positive attitude towards conservation despite disturbing human mortality records(22deaths in the last five years) from the reserve area and surrounding. Awareness of wildlife behavior together with conservation and easy access to compensation schemes were suggested to minimize conflicts in the area.