红豆草在旱地土壤的生产性能和农化性状的研究

三年研究结果表明,在陇东黄土旱地春播红豆草(Onobrychis Viciaefolia Scop),第二年产量最高,地下部分生物量增加最多。不同生活年限的红豆草对土壤主要农化性状影响不同:第二年生活的红豆草对耕层土壤培肥效应较显著,土壤有机质和含氮量的净增值最大,土壤微生物总数增加,有益微生物的活动旺盛,土壤有效养分略有增加.     

红豆草在旱农地区固氮肥田作用研究(Ⅰ)

本文研究了红豆草(Onobrychis Viciaeffolia Scop)在旱农地区的结瘤固氮作用。研究表明,在该地区红豆草结瘤状况良好,单株根瘤量多达1.9—3.0克,但多属无效根瘤。用乙炔还原法测定根瘤的固氮活性为0.048毫微克乙烯分子/毫克根瘤/分钟。此外,研究了红豆草结瘤固氮的环境因素(包括土壤有效养分、微量元素及水分、光照等)。研究认为,在该地区肥力较低的土壤,需要施用一定氢肥,这对提高红豆草的经济产量是重要的。     

黄土丘陵沟壑区林草间作对土壤养分的影响——以甘肃省庄浪县为例

以不同林草间作模式为对象,以相同立地条件下的农田作为对照,对林草间作地土壤养分变化进行了测定分析,结果表明:在黄土高原丘陵沟壑区实施林草间作,在一定程度上有利于提高土壤养分含量和营养水平.5种间作模式对土壤养分含量和营养水平的影响程度大小依次为:山杏×紫花苜蓿>山杏×红豆草>油松×紫花苜蓿>油松×红豆草>沙棘×紫花苜蓿;林草间作对土壤有机质和土壤全氮含量的影响较为显著,而对土壤全磷、全钾含量的影响相对较小;从影响的土层深度看,林草间作对40 cm以上土壤养分含量的影响要比对60 cm层的影响更为明显.     

不同生长年限对紫花苜蓿产量及土壤养分的影响

研究了不同生长年限(2、5、6、7和10年生)对紫花苜蓿(Medicago sativa L.)草产量及土壤养分的影响。结果表明,随生长年限的增加,紫花苜蓿产量呈先增加后降低趋势,以7年生紫花苜蓿产量最高,与其他生长年限均达显著差异水平(P<0.05);土壤含水量和电导率呈先增加后降低趋势,而土壤容重、总孔隙度和p H呈先降低后增加趋势,表明了紫花苜蓿具有显著的脱盐功能;土壤养分随生长年限的增加呈先增加后降低趋势,整体表现为:7年生>10年生>6年生>5年生>2年生,各生长年限紫花苜蓿土壤氮素和钾素变化幅度较大,土壤全磷和有效磷含量差异并不显著(P>0.05);垂直方向随着土层深度的增加,各生长年限紫花苜蓿土壤养分呈降低趋势,表现出明显的"表聚性",并且各生长年限紫花苜蓿土壤养分储存于0~20 cm土层。相关性分析表明,紫花苜蓿土壤养分与相应的有效养分和含水量呈极显著正相关(P<0.01),与电导率和pH呈极显著的负相关(P<0.01),而p H和电导率之间极显著正相关(P<0.01),由此可见,生长年限对紫花苜蓿土壤养分的影响是土壤理化等因子的共同作用结果。     

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轮作及整地。红豆草以各种禾谷类作物为前茬，轮作年限以3年为宜，连作病虫害严重。红豆草可生长于干燥贫瘠的砂砾土、沙土。整地要求不严。     

红豆草的产量和营养成分的研究

近年来红豆草的栽培引起国內外草原牧草工作者的普遍重视。我校牧草试验站是农牧渔业部部商投资的红豆单种子繁殖基地,向全国各地提供红豆草良种。为了加速红豆草的大面积推广。对其两个主要生产能力指标——产量和营养成分进行了较系统的研究,其中包括红豆草不同生活年限、不同生育期的产草量动态;不同生活年限的种子产量动态;不同生育期牧草和种子的营养成分,氨基酸含量;不同刈割期的根系重量、根系贮藏营养物质以及根瘤量和根瘤化学成分等。研究表明,红豆草的产量高、品质好,是我国北方干旱和半干旱地区很有发展前途的优良豆科牧草之一。     

覆草对苹果园土壤养分和微生物的影响

为了解覆草苹果园土壤养分的变化特征,以沈阳农业大学果树实践基地6年生寒富苹果为研究对象,研究果园覆草对土壤养分、微生物生物量以及土壤酶活性的影响。结果表明:与清耕处理相比,多年覆草可改善果园土壤养分状况,显著提高果园表层土壤养分含量。覆草处理显著提高了表层土壤微生物生物量,但覆草处理的促进作用随土层的加深而减小,在30~40 cm深土层中,覆草处理的微生物生物量与清耕处理基本相同。土壤酶活性的高低能反映土壤微生物活性和生化反应强度,覆草处理能提高土壤酶的活性,但随着土层的加深而降低。     

三峡库区坡改梯土壤养分状况与变化趋势

为准确掌握三峡库区坡改梯工程实施后的土壤肥力状况,以巫山县为例,采用时空代换法分析其不同年限坡改梯土壤的养分状况及其变化趋势。结果表明:研究区土壤肥力总体较低,根据全国第二次土地普查土壤养分分级标准,其全氮、速效钾、有机质和速效磷含量均值分别处于三级、三级、四级和五级标准,土壤养分的空间异质性较小。相较于坡耕地,坡改梯土壤养分随着耕种年限的增加总体呈上升趋势。坡改梯年限为2年的土壤养分各指标的均值相对于坡耕地土壤有所降低且土壤肥力差异性最大,坡改梯年限为14年的土壤养分各指标的均值呈直线上升趋势且土壤肥力差异性减小。     

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为准确掌握三峡库区坡改梯工程实施后的土壤肥力状况,以巫山县为例,采用时空代换法分析其不同年限坡改梯土壤的养分状况及其变化趋势.结果表明:研究区土壤肥力总体较低,根据全国第二次土地普查土壤养分分级标准,其全氮、速效钾、有机质和速效磷含量均值分别处于三级、三级、四级和五级标准,土壤养分的空间异质性较小.相较于坡耕地,坡改梯土壤养分随着耕种年限的增加总体呈上升趋势.坡改梯年限为2年的土壤养分各指标的均值相对于坡耕地土壤有所降低且土壤肥力差异性最大,坡改梯年限为14年的土壤养分各指标的均值呈直线上升趋势且土壤肥力差异性减小.     

不同年限地表覆盖对毛竹林土壤酶 及土壤养分的影响

为了解不同年限地表覆盖对毛竹(Phyllostachys edulis)土壤酶、土壤养分的影响,以浙江省台州市黄岩区山地毛竹林为研究对象,对覆盖1年翻土、覆盖2年翻土和自然生长(对照)的毛竹林0～50 cm土层土壤酶活性及土壤养分含量进行了比较研究。结果表明:(1)随着毛竹林地表稻草覆盖年限的增加,土壤多酚氧化酶活性和过氧化物酶活性表现下降的趋势,且随土层深度的增加而逐渐减小;和对照相比,部分土层差异达到显著水平;土壤脲酶和蔗糖酶的活性随着覆盖年限的延长而提高,在10～20 cm土层达最大值;与对照样地相比,地表覆盖后,土壤脲酶和土壤蔗糖酶活性均较高,并且在部分土层差异达到显著水平。(2)各层土壤养分含量都随着覆盖年限的延长而增加,覆盖后,10～20 cm土层处土壤养分元素含量达到最大值。(3)地表稻草覆盖后,土壤养分含量和土壤酶活性之间具有相关性,土壤全氮、有效磷等含量与多酚氧化酶活性之间呈负相关关系,而土壤各养分元素含量和土壤脲酶、蔗糖酶活性之间呈显著正相关关系。毛竹林地表稻草覆盖后,土壤中不同酶的活性随着覆盖年限的延长而呈现不同的变化趋势,土壤养分含量随着地表稻草覆盖年限的增加也有增加的趋势,因此土壤酶和土壤养分以及它们之间的相关性可以作为评价土壤肥力的指标。     

Mapping management zones in a sandy pasture soil using an objective model and multivariate techniques

Soils occupied by dryland pastures usually have low fertility but can exhibit a high spatial variability. Consequently, logical application of fertilisers should be based on an appropriate knowledge of spatial variability of the main soil properties that can affect pasture yield and quality. Delineation of zones with similar soil fertility is necessary to implement site-specific management, reinforcing the interest of methods to identify these homogeneous zones. Thus, the formulation of the objective Rasch model constitutes a new approach in pasture fields. A case study was performed in a pasture field located in a montado (agrosilvopastoral) ecosystem. Measurements of some soil properties (texture, organic matter, nitrogen, phosphorus, potassium, cation exchange capacity and soil apparent electrical conductivity) at 24 sampling locations were integrated in the Rasch model. A classification of all sampling locations according to pasture soil fertility was established. Moreover, the influence of each soil property on the soil fertility was highlighted, with the clay content the most influential property in this sandy soil. Then, a clustering process was undertaken to delimit the homogeneous zones, considering soil pasture fertility, elevation and slope as the input layers. Three zones were delineated and vegetation indices (normalized difference vegetation index, NDVI, and normalized difference water index, NDWI) and pasture yield data at sampling locations were employed to check their differences. Results showed that vegetation indices were not suitable to detect the spatial variability between zones. However, differences in pasture yield and quality were evident, besides some key soil properties, such as clay content and organic matter.

     

Spatial variability of soil properties and yield of a grazed alfalfa pasture in Brazil

Knowledge of the spatial variability of soil properties and of forage yield is needed for informed use of soil inputs such as variable rate technology (VRT) for lime and fertilizers. The objective of this research was to map and evaluate the spatial variability of soil properties, yield, lime and fertilizer needs and economic return of an alfalfa pasture. The study was conducted in a 5.3 ha irrigated alfalfa pasture in Sao Carlos, SP, Brazil that was directly grazed and intensively managed in a 270-paddock rotational system. Alfalfa shoot dry matter yield was evaluated before grazing. Soil samples were collected at 0–0.2 m depth, and each sample represented a group of 2 or 3 paddocks. Apparent soil electrical conductivity (ECa) was measured with a contact sensor. The cost of producing 1 ha of alfalfa was estimated from the amount of lime and fertilizer needed and was then used to estimate the total cost of production for the dairy system. The alfalfa dry matter yield was used to simulate the pasture stocking rate, milk yield, gross revenue and net profit. The spatial variability of soil properties and site-specific liming and fertilizer needs were modeled using semi-variograms with VESPER software, the soil fertility information and economic return were modeled with SPRING software. The results showed that geostatistics and GIS were effective tools for revealing soil and pasture spatial variability and supporting management strategies. Soil nutrients were used to classify the soil spatial distribution map and design site-specific lime and fertilizer application maps. Spatial variation in forage and spatial estimates of stocking and milk yield are adequate pasture management tools. Spatial analyses of needs, forage availability and economic return are management tools for avoiding economic problems, as well as potential environmental problems, caused by unbalanced nutrient supplies and over- or under-grazing.     

Effects of Cropping System Change for Paddy Field with Double Harvest Rice on the Crops Growth and Soil Nutrient

The effects of the cropping system change for paddy field with double harvest rice on crops growth and soil nutrient in red soil were studied. The results indicated that the economic benefit and the ratio of the output to input were all increased in terms of the market price for the crops under various treatments. The greatest economic benefit was obtained in the treatment of paddy-upland rotation, and the corresponding economic benefit was increased by 34.7, 21.4, and 2.2% in comparison with that of control （rice-rice-astragali）, pasture, and upland cropping treatments. The economic benefits in pasture and upland cultivation treatments were increased by I 1.0 and 31.8%, respectively, when compared with that of the control treatment （CK）. The ratio of output to input in pasture, paddy-upland rotation, and upland cropping treatments was enhanced by 0.9, 0.6, and 0.3, respectively, in comparison with that of control. To grow pasture is beneficial for improving soil fertility since the contents of soil organic matter, total nitrogen, total phosphorus, and available phosphorus are all enhanced significantly. However, the concentrations of the soil available nitrogen, the total potassium, the available potassium were somewhat reduced in all the treatments, suggesting that increasing the input of nitrogen, particularly potassium, was necessary under the present fertilization level. Based on the conditions of fertility, climate, cultivation, and management of paddy field with double harvest rice in red soil regions, it is feasible to alter the cultivation system of paddy field with bad irrigation condition. In particular, cultivation systems such as pasture and paddy-upland rotation can be selected to extend because better economic benefit and improvement of soil fertility in the purpose region were obtained.     

Characteristics of C and N Accumulation in Infertile Red Soil Under Different Rotation Systems

A long-term experiment was conducted at the Ecological Experimental Station of Red Soil, Chinese Academy of Sciences to investigate the characteristics of material cycling and C, N accumulation in infertile red soil under different treatments of rotation systems for 11 years. Plant biomass, amount of organic materials returned to the soil, and budget of nitrogen in soil were obviously different under conventional cultivation, coverage by shrubs ( Lespedeza formosa ), rotation of shrubs ( Lespedeza formosa ) and crops (PeanutBuckwheat). Rotation of shrubs and crops with a combination of rational fertilization would be 75 - 100% of biomass and a similar amount of organic materials returned to the soil compared with that under coverage shrubs, more input than output of nitrogen, high system stability, and increasing crop productivity. With distinct cycling, different treatments of rotation systems influenced discriminatorily soil fertility. Soil organic carbon and nitrogen were respectively less than 7 and 0.6 g kg-1 for conventional cultivation, 9- 11 and 0.6-0.9 g kg-1 for rotation of shrubs and crops, 14 - 16 g kg-1 and more than 1 g kg-1 for coverage by shrubs after 11 years, which represent low, middle and high levels of upland red soil fertility at the current situation. It implied that with cultivation system and fertilization measures, the infertile red soil could have middle to high fertility after about 10 years rational utilization. Comparison of results from different treatments showed that a large loss of organic carbon and nitrogen was caused by soil erosion which resulted in a low level of C and N in upland red soil. It could be suggested that increasing carbon storage in infertile red soil would sequester a great amount of atmospheric CO2 and mitigate the global warming potentially.     

炼山后杉木幼林地土壤肥力动态研究

本文通过连续四年定位研究,结果表明:炼山后一段时期内（几个月至一年）,林地土壤肥力和土温得到短期提高,但土壤全N和有机质因高温挥发而有所降低;随后因炼山林地裸露,水土流失加剧,土壤肥力各指标呈逐年下降趋势;至第四年又表现出回升趋势。说明炼山一方面加快杉木人工林生态系统的养分循环,另一方面又干扰和破坏生态系统的养分循环的格局。     

茶陵县杂交中稻测土配方施肥效应模型研究

通过连续6a的田间试验,分析比较了茶陵县杂交中稻的相对产量、相对吸收量与土壤肥力的关系,根据杂交中稻的N、P、K养分相对吸收量划分土壤N、P、K丰缺指标。采用三元二次回归,建立了不同肥力条件下杂交中稻的N、P、K肥料效应模型,依据模型提出了不同肥力水平（目标产量）下杂交中稻的测土配方最佳施肥用量及施肥技术。     

影响红豆草开花结实诸因素的探讨

本文通过不同因素对红豆草的开花数、结果率.种子产量及品质影响的观测结果表明.红豆草属于典型的异花授粉植物,昆虫传粉对种子产量及品质的提高具有十分显著的作用;低播量、宽行距、施适量的氮磷肥料、适时灌溉对红豆草种子生产亦有良好的效果。     

武威市山地旱作土壤资源的评价

本文经过土壤调查、土壤理化性质的测定及数字整理,总结出武威市山地旱作土壤土层深厚,潜在肥力较高,土体结构较好。存在的主要问题是:干旱缺水,烧草皮,踏灰,陡坡处开荒破坏了植被,导致了水土流失严重,供肥性能差,速效氮偏低,速效磷缺乏。根据以上特征,制定旱作土壤(耕层)三级肥力指标,为旱作土壤改土和培肥提供了科学依据。     

绵羊对红豆草的采食率和消化率

本文报道用全收粪法测定了绵羊对红豆草二槎青干草的采食率和各种营养物质的消化率。在以绵羊体重4%供给红豆草干物质的条件下,测得绵羊对红豆草二槎青干草干物质的采食率为80.61±3.41%。干物质消化率为:60.29±0.28%;有机物为60.72±0.27%;粗蛋白质为56.11±0.86%;粗脂肪为57.46±6.50%;粗纤维为43.88±2.00%;粗灰分为40.65±1.04%;无氮浸出物为72.36±0.63%;钙为12.07±11.05%、磷为22.55±7.98%。试验期间绵羊增重快,说明红豆草确实为优良的豆科牧草。     

不同种植年限日光温室土壤肥力与土壤酶活性的变化规律

【目的】研究日光温室土壤酶活性和土壤肥力随种植年限的变化趋势,为日光温室科学施肥管理提供依据。【方法】选取兰州市皋兰县露地（对照,CK）及种植年限分别为1,3,5,10,15年的日光温室土壤作为供试材料,分析土壤养分含量和土壤酶活性的变化规律及其相互关系。【结果】研究区内温室土壤有机质含量处于中下等水平,而氮、磷、钾的含量较高。随着种植年限的增长,研究区内温室土壤有机质、氮素、磷素、钾素含量基本呈上升趋势,种植年限与土壤全磷、全钾、速效磷含量的相关性达到极显著水平,与有机质、全氮、碱解氮、速效钾的相关性达到显著水平;土壤脲酶和蔗糖酶活性总体呈下降趋势,蛋白酶和过氧化氢酶活性则保持相对稳定水平,种植年限与脲酶活性的相关性达到显著水平,与蔗糖酶、蛋白酶、过氧化氢酶活性之间的相关性不显著。土壤脲酶与有机质、全氮、速效磷和速效钾均呈显著负相关关系,蔗糖酶与全磷呈显著负相关关系,蛋白酶和过氧化氢酶与各土壤养分相关性均不显著。【结论】为维持日光温室土壤的可持续高效生产,应多施优质有机肥,同时还应适当减少化肥的施用量。