旅游干扰对峨眉山风景区土壤及植被的影响

文章利用室外调查与室内分析相结合的方法,分析了旅游干扰对峨眉山景区内的植被与土壤性质的影响。试验结果表明:旅游干扰对峨眉山景区中的植被影响比较明显,植被均匀度指数、丰富度指数、优势度指数以及多样性指数都低于对照区,其中草本层所受到的影响最为严重,达到显著水平(P0.05)。在干扰活动下,草本层的均匀度指数、丰富度指数、优势度指数及多样性指数分别比对照降低了13.42%、29.81%、10.12%及17.69%。此外,旅游干扰也对景区土壤性质造成较大影响,干扰使土壤容重进一步增加,同时降低了土壤有机质、全氮、全钾及速效养分的含量,在对不同土层深度分析中表明,干扰区土壤各理化性状随着土层深度的增加而增加,而对照区土壤各理化性状随着土层深度的增加而减少,旅游干扰对土壤理化性质影响显著。     

青海高原土壤培肥经济效益刍议

通观土壤培肥实践,概括起来主要有三种基本类型:一是以增施有机肥,种植绿肥、豆科作物、牧草,秸秆还田等措施培肥土壤的生物培肥;二是通过增施化肥,按比例地供给各种无机营养元素,提高土壤供素水平的化学培肥;三是利用修建梯田,平整土地,种草护坡,控制水土流失等物理调节方法,以保促养的工程培肥。无论那种培肥     

培肥土壤的六种途径

因化肥施用过多,有机肥投入少,耕作不合理等原因,目前土壤越种越薄,培肥地力已刻不容缓。地力的培肥和提高,应从改造土壤环境条件和土壤属性两个方面着手,其途径有六种:1.搞好农田基本建设根据制约土     

玉米追肥浇水五误区

误区一:基肥不足追肥代用优质农肥做基肥,能增加土壤有机质和土壤团粒结构,为玉米的生长发育提供所需要的各种营养元素。而化肥就不具备这个优点。“基肥不足追(化)肥代”,只能使土地越种越瘦,越种越板结。     

水稻高产施肥原则及注意事项

水稻要高产,施肥最关键,现将水稻高产施肥原则和注意事项介绍如下: 基本原则 重施化肥,配合有机肥:有机肥与无机肥配合施用,改良培肥土壤的效果十分显著,能提高土壤有机质贮量,改善土壤有机质组成,增加土壤中氮、磷、钾和微量元素的含量,加强土壤的保肥性和供肥性,改善土壤物理性质和水分状况.     

黑龙江省主要土壤代换量水平及其与有机质关系

土壤阳离子代换量基本上代表了土壤可以吸收养分的数量,也即土壤的保肥能力,它是衡量土壤供求状况的重要指标,也是改良土壤与合理施肥的重要依据。但目前对土壤掌握和应用的程度还不够。施用化肥的实践中往往是保肥力低的土壤,施用化肥量高,这就造成肥料的很大浪费,致使生产成本高,效益下降;同时过量的施肥还造成土壤结构的破坏,恶化了土壤的物理性质。由此可见,探讨我省土壤代换量的水平对于指导施肥与改良土壤具有十分重要的价值。     

沼肥在蔬菜生产上的应用

一、沼肥作基肥 沼液处理能明显提高蔬菜作物的产量，提高蔬菜商品果合格率。沼肥中含有丰富的有机质和其他营养成分，长期使用沼肥作基肥可培肥地力，减少化肥的使用量，减轻农业污染，提高土壤有机质含量，使土壤疏松、结构优化，可解决长期使用无机肥而造成土壤板结问题。     

水稻正确施肥方法

有机肥与化肥搭配使用。有机肥富含有机质，可以培肥土壤，提供多种营养成分，还能提供具有生长素和激素性质的化合物。施用有机肥料有助于保持水稻士壤中氮元素的储量。有机肥养分释放缓慢，而化肥多为速效肥，养分供应快，两者搭配使用，可使养分供应较为平稳。有机肥中的有机酸和腐殖酸能与上壤中的铁、铝结合，减少磷肥被土壤固定，提高有效磷量和磷肥在土壤中的循环。     

关于发展有机农业的调查报告

当前农村种地不养地的掠夺式农业生产情况相当严重,忽视农家肥、主要靠化肥增加生产,致使土壤的有机质不断下降,这对农业生产的稳定增长是很不利的。最近,我和王显堂等几位同志带着这个问题进行了调查。我们到了铁岭市的昌图、开原、铁岭县和沈阳市新城子区,找市县领导和基层同志以及省市有关专家、农业部门进行了座谈。(一) 目前,我省农村重化肥、轻农肥的现象日益严重,形成了“化肥热”。增施化肥对粮食增产是有很大作用的。因此,农民购买化肥的积极性越来越高。随之,便产生了两种情况:一是当前化肥产量有限,满足不了需要,出现了争化肥、炒化肥、抢化肥的局面,造成化肥价格飞涨,粮食成本提高。二是单纯追求化肥、忽视农肥的施用,致使土壤有机质减少,地力下降,农业生产后劲不足。     

长期不同施肥处理对棕壤不同组分有机碳的影响

以沈阳农业大学棕壤长期定位试验站土样为材料,对长期施肥条件下不同施肥处理土壤有机碳、活性有机碳和颗粒有机碳进行了研究.结果表明:有机肥配施化肥有利于提高棕壤有机碳含量,长期不同施肥处理对土壤水溶性有机碳和微生物量碳的影响差异显著,高量有机肥与化肥配施处理含量最高,长期施用化肥降低了土壤颗粒有机碳含量,有机肥的施用可以显...     

长期不同施肥处理对黑土不同组分有机碳的影响

以吉林省农业科学院土壤肥料研究所"国家黑土肥力与肥料效益长期定位监测基地"土样为材料,对长期施肥条件下不同施肥处理土壤有机碳、活性有机碳和颗粒有机碳进行了研究。结果表明:有机肥配施化肥有利于提高黑土有机碳含量,长期不同施肥处理对土壤水溶性有机碳和微生物量碳的影响差异显著,高量有机肥与化肥配施处理含量最高,长期施用化肥降低了土壤颗粒有机碳含量,有机肥的施用可以显著提高黑土有机碳含量。     

Economic analysis of different options in integrated pest and soil fertility management in maize systems of Western Kenya

The major biotic constraints to the production of maize, the major staple food in Western Kenya, are field pests such as Striga and stem borers, and low soil fertility. To counter these constraints, new cropping systems have been developed, including “push‐pull,” rotations with promiscuous soybean varieties and green manure crops, and imidazolinone resistant‐ (IR‐) maize. To analyze the technical and economic performance of these technologies, both with and without fertilizer, on‐farm researcher‐managed long‐term trials were implemented over six seasons in two sites each in Vihiga and Siaya districts of Western Kenya. The economic results, based on marginal analysis using a multioutput, multiperiod model, show that the new cropping systems with fodder intercropping (push‐pull) or soybean rotations were highly profitable. Push‐pull is more profitable but requires a relatively high initial investment cost. Green manure rotation, IR‐maize, and fertilizer all increased yields, but these investments were generally not justified by their increased revenue. We argue that research on rotation and cropping systems to tackle pest and soil fertility problems in Africa deserve more attention. This will require increased collaboration between agronomists and economists to set up long‐term experiments with new cropping systems to develop proper economic models.     

河南省不同典型农业生产区玉米施肥现状及增产潜力评价

[目的]通过调研2017年河南省不同典型农业生产区玉米的施肥现状,发现河南省玉米种植效益普遍较低主要与化肥不合理施用相关,提出相应的施肥建议以获得最大增产。[方法]采用实地问卷调查的方法,选择河南省禹州、长葛(两个粮食作物种植区)、杞县(一个经济作物种植区)3个典型农业经济区域作为调查地点,共调查了828家农户玉米的产量、施肥种类、施肥量、施肥时间、施肥方式等。[结果]河南省粮作区玉米产量为4 500.00～10 500.00kg/hm~2,养分投入量为90.00～1 249.00kg/hm~2,且仅有单质肥料和复合肥的投入,禹州、长葛两地粮作区平均PFP分别为19.18%和22.46%,、增产潜力分别为23%和26%;杞县经作区玉米产量在4 731.00～11 320.00kg/hm~2,养分投入量为0.00～1 206.00kg/hm~2。经作区有机肥的投入,使其肥料种类相对较多,该区域平均PFP为31.19%,平均增产潜力为34%。[结论]根据当地土壤肥力,粮作区玉米种植可适当减少氮肥投入量,降低基追比,增施磷钾肥,改进后玉米有20%～30%的增产潜力;经作区玉米种植严格把控氮磷钾的配施,增施有机肥,增加基肥种类,改进后玉米有30%～40%的增产潜力。     

东北典型黑土区耕地地力评价与障碍因素诊断

研究目的:从影响耕地地力的土壤管理、理化性质、土壤养分、剖面性状、立地条件和气候条件等6个方面选取13个评价指标对东北典型黑土区耕地地力进行综合评价,并在评价基础上进行障碍因素诊断,为今后定量化分析耕地地力障碍因素提供方法。研究方法:该研究运用层次分析法和模糊数学法等方法进行耕地地力评价,并引入障碍度模型对影响该区域耕地地力的障碍因素进行定量化分析。研究结果:(1)东北典型黑土区耕地地力整体呈现南高北低的趋势,其中以中等地(四、五、六、七等地)为主,占研究区总耕地面积的64.47%;其次为高等地(一、二、三等地),占研究区总耕地面积的28.31%;低等地(八、九、十等地)最少,只占研究区总耕地面积的7.22%;(2)对研究区评价指标体系中耕层厚度、有机质、有效磷、p H、灌溉能力、排涝能力6个指标进行障碍度分析,发现除有效磷和p H对耕地地力障碍作用不明显外,其他因素均有明显障碍作用,且障碍程度呈现一定的规律性。研究结论:(1)通过对研究区进行耕地地力评价,对东北典型黑土区的耕地数量和质量在空间分布特征上有了全面掌握,为今后耕地的合理利用提供了依据;(2)障碍度模型的引入为分析影响耕地地力的障碍因素提供了定量化的研究方法,为耕地地力保护和提升研究提供了方法支撑。     

Do fertilizer subsidies crowd out organic manures? The case of Malawi

We assess the impacts of the Malawian Farm Input Subsidy Program on manure use at the farm plot level using more than 3,000 farm plot observations from six districts in central and southern Malawi over three years (2006, 2007, and 2009). The probabilities and intensities of manure use were investigated with the correlated random effects (CRE) probit and tobit models. The endogeneity of access to fertilizer subsidies and fertilizer use intensity was controlled for with a control function approach. Both the probability of manure use and intensity of manure use were positively correlated with the intensity of fertilizer use. A 1% increase in fertilizer use intensity is associated with a 1.94%–1.96% increase in the intensity of manure use outside the subsidy program and a 0.62%–1.66% increase in manure use with the subsidy program. A 1% increase in average fertilizer price was associated with a 0.43%–0.76% increase in the probability of manure use and a 3.5%–5.3% increase in the intensity of manure use.     

华北平原小麦—玉米轮作对奶牛粪肥的消纳能力研究

奶牛粪便富含植物营养物质,制作粪肥还田对提高土壤养分、改善土壤质量、提高作物产量以及解决牛场环境污染均具有重要的意义。文章设计了空白(CK)、习惯施肥(NPK)和不同粪肥量M30、M60、M120、M240处理,开展不同施肥模式对小麦玉米产量、土壤肥力及硝态氮残留等方面的研究。研究结果表明,连续施用两年粪肥后,粪肥施用量较高的M120、M240处理小麦玉米籽粒产量、秸秆产量、土壤全氮和速效钾含量均高于NPK处理;施用粪肥均提高土壤有机质和速效磷的含量。施用粪肥与常规施肥相比,在0~200cm的土壤剖面上NO~-_3-N分布特征完全不同,施用粪肥各处理土壤NO~-_3-N除在耕层含量较高外,耕层以下含量均较低,且差异较小。0~200cm土壤剖面NO~-_3-N累积量随着粪肥的增加而增加,6月份0~200cm粪肥各处理NO~-_3-N累积量均低于NPK处理,10月份NO~-_3-N累积量M240处理高于NPK处理,表现出过量施用粪肥造成NO~-_3-N大量累积。     

北方半干旱区氮肥不同配施方式对小南瓜产量的影响

小南瓜是北方半干旱区增加经济产值的适生作物之一。研究选用日本赤甘栗品种,采用田间小区试验,研究了在两种灌溉方式(灌溉、灌溉施肥)和四个牛粪氮添加水平(25、50、75、100 kg N/hm~2)处理下氮肥不同配施方式对小南瓜产量的影响。结果表明,在小南瓜生长前期,滴灌施肥方式可有效促进叶绿素的积累及叶片的复壮,有利于植株生长。单施有机肥组,随着牛粪氮添加水平的增加小南瓜产量未见明显增加,平均产量为10 t/hm~2;有机肥结合灌溉施肥组,随着牛粪氮添加水平的增加小南瓜产量显著增加,最高达到21.5 t/hm~2。当总氮添加量为100~140 kg/hm~2,有机无机肥配比为3:7~5:5时,小南瓜产量比单施牛粪肥增产60%,平均达到16 t/hm~2。     

Participatory trials and farmers' social realities: understanding the adoption of legume technologies in a Malawian farmer community

This article presents results from a study exploring the reasons for low adoption of legume technologies to improve soil fertility by farmers from a community in central Malawi who took part in participatory trials. This study explores the influence of gender roles in agriculture and land ownership and socio-economic differentiation in the community. Because most women do not own land and are traditionally responsible for legume crops, they have little interest in managing soil fertility for maize crops. Men are not interested in using legumes in maize-cropping systems. Some are too poor: this group needs to complement their subsistence maize production with paid labour on the farms of better-off farmers; restricting the labour availability for their own farming activities. Wealthier farmers have access to, and prefer to use chemical fertilizer and cattle manure. Take-up rates among the middle group of farmers were also low. This study discusses how these (and other) factors influence the (non-)adoption of maize-legume technologies in Malawi and the effectiveness of participatory research. It emphasizes how differentiated farmer-realities affect the uptake of technologies identified as promising in participatory field evaluations.     

Long-term effects of crop residues and fertility management on carbon sequestration and agronomic productivity of groundnut–finger millet rotation on an Alfisol in southern India

The data from long-term management and cropping systems experiments are needed to assess changes in soil quality, organic carbon pool, and agronomic sustainability. Thus, a 13-year-old soil fertility management experiment was used to assess the impact of crop residues carbon (C) inputs on SOC stock in a rainfed groundnut (Arachis hypogeae L.)–fingermillet (Eleusine coracana (L.) Gaertn) rotation in semiarid alfisol. The application of farmyard manure (FYM) alone or in a combination with chemical fertilizers contributed to higher amounts of C inputs and subsequently to build up a higher SOC pool. Application of 10?Mg?ha^?1 of FYM and a recommended dose of chemical fertilizer (25:21.8:20.7 and 50:21.8:20.7?kg?N, P, K ha^?1 for groundnut and fingermillet, respectively) increased soil SOC pool by 41.2% to 73.0?Mg?ha^?1 with an increase of 9.3?Mg?ha^?1 over 13 years. Both SOC pool and rates of its sequestration were positively correlated with cumulative C input and sustainable yield index. A minimal input of 1.62?Mg?C?ha^?1?yr^?1 is needed to maintain SOC pool at the antecedent level. Balanced application of NPK fertilizers is needed to reduce and reverse the depletion of SOC pool.