基于SWAT模型的农业施肥对梅江流域营养盐产出变化的影响分析

以梅江流域为研究区域,基于SWAT模型构建适用于该流域的氮磷污染负荷模型,模拟分析了农业施肥影响下的流域内氮、磷营养盐产出的时空分布变化特征,为该流域营养盐污染控制和综合治理提供有益参考。结果表明:1)研究区氮、磷营养盐产出的增加与农业化肥的施用有关,在时间变化上,2011年流域内总氮和总磷的产出分别增长了99.33 mg/L和17.64 mg/L,总氮、总磷负荷产出的增加主要集中在4—8月,分别占全年总产出的87.3%和68.5%;2)在空间分布上,总氮、总磷污染负荷变化的空间分布特征基本一致,均集中在研究区的中部和北部。

平衡施肥技术在现代农业施肥中的作用

随着我国经济的快速增长,综合国力的提升,使得我国的人口增长速度急剧增长,而人口的暴增直接带来的影响就是粮食短缺,尤其是在新中国刚成立初期,粮食问题尤为明显,因为我国本身在世界上就是人口大国,所以人口基数就比较大。再加上近几年,我国的快速发展,更是进一步加大了我国人口和粮食需求之间的矛盾。对此,为了有效的解决这一问题,就需要大力发展我国的现代农业。近几年,我国科技技术的复兴,使得现代农业中出现了很多的新技术,而平衡施肥技术就是其中的佼佼者。平衡施肥技术依靠技术本身的优势可以很好的改善土壤本身的土质,并且,这种技术还从生态角度上相当贴切,从而实现农业可持续发展。对此,本文就以平衡施肥技术在现代农业施肥中的作用进行着重探讨,为相关的农业工作者提供参考。

有机农业栽培的施肥与土壤培肥技术探讨

为了进一步推动我国有机农业的发展,需要充分考虑有机农作物的生长效率,综合规划有机农业栽培施肥管理,提高施肥的效果和质量,适当调整土壤的肥力程度,维护土壤环境的协调稳定发展,进一步考虑农作物的生长规律,应用具有针对性的土壤培肥技术。

有机农业栽培的施肥与土壤培肥技术分析

现阶段,我国人民群众已经对农作物质量予以高度关注,希望购入有机农业产品,因此农作物生产不能只靠产量取胜,而是应当做到产量和质量并重。在种植农作物过程中,施肥与培肥的过程尤其重要。在科学合理地运用肥料以后,既能够提高农作物的种植产能,还可以使土壤内部的肥力得到调节,从而使土壤育肥目标得以实现。基于此,本文站在有机农业栽培角度,分析农作物种植过程中的施肥以及土壤培肥技术。

浅谈土壤养分平衡与农业施肥的关系

中国化肥消费量巨大,有机肥养分资源数量及农田养分输入时空分布特征不明确,制约了养分资源合理分配与高效利用,研究农田养分投入产出与平衡及农业生产对养分的需求,可为养分资源的科学管理提供科学对策。本文分析了土壤养分与植物生长关系及营养元素的相互作用效应,论述了土壤养分平衡调控,为农业施肥提供理论依据。

基于模糊层次综合评价模型的农业安全施肥评价

为综合评价农业安全施肥状况,选取9个评价指标,按照5级评价标准,利用层次分析法确定各指标权重,构建农业安全施肥模糊层次综合评价模型.结果表明,研究区农业安全施肥等级从2006到2011年逐年好转,预测到2015和2020年将达到较安全状态.评价结果符合区域实际情况.

基于GPRS DTU的农业灌溉施肥智能化控制系统的应用研究

本文介绍一种智能化的灌溉施肥的控制系统,可以按照农作物的生长需求,对其进行智能化的灌溉。首先描述了整个系统的构成系统的核心控制器是HORNER OCS,通过核心控制器来构建出整个农业灌溉施肥控制系统。通讯模块使用的是GPRS DTU,变频器来保证整个系统的压力调节。经过研究,这种系统的功能是非常完善的,并且运行起来也比较稳定,可以有效地满足农业水肥的管理。

关于施肥对农业生态环境的影响及对策分析

十八大以来生态环境保护被提到新的高度,无论是工业还是农业,都在贯彻落实相关方针,减少对生态环境的消极影响。农业是我国经济发展的基础,属于第一产业,而在整个农业发展过程中施肥是必然的步骤,在新时期,施肥这一过程受到高度重视。目前对其研究的主要方向是掌握其对生态环境的影响,分析出负面影响,找到相关解决措施,从而减少施肥对生态环境的负面影响,以提高新时期农业发展活力,为经济发展打下坚实的基础。

链条输送式变量施肥抛撒机的设计与试验

针对国内变量施肥机作业幅宽小,变量施肥抛撒机缺乏的问题,该文应用变量施肥技术,设计了一种基于处方图的链条输送式变量施肥抛撒机。通过分析肥料颗粒在撒肥盘上的运动和受力,建立了肥料颗粒在脱离撒肥机圆盘过程中的运动方程,设计并确定了变量抛撒控制系统、肥箱、肥门自动开启装置等关键部件的结构及参数。并进行了不同施肥量和抛撒均匀性的试验,结果表明:链条输送式变量施肥抛撒机变量效果较好,且具有较好的抛撒均匀性,在拖拉机速度1.5m/s,实际施肥量与预置施肥量相对误差最大值为7.53%;拖拉机速度2m/s,目标施肥量225kg/hm2,抛撒幅宽设定30m,有效幅宽抛撒变异系数为14.90%,能够较好的满足实际生产要求。

智能施肥机自动控制系统的分析

我国目前的农业施肥技术虽然取得了一定的进展,但是创新性的研究还有待加强。文章分析了智能施肥机自动控制系统的工作内容、工作原理和主要功能,同时对自动控制技术的总体设计方案、软件技术、通讯技术和相关技术的设计情况进行了研究分析。

黑龙江省化肥利用现状及对策

分析了当前黑龙江省不同类型土壤、不同地区农作物的化肥用量及比例、施肥方法、施肥制度及化肥使用现状 ,查明了障碍化肥利用率提高的限制因素 ,指出了提高化肥利用率的技术与措施 ,以达到增加作物产量、改善品质及增强作物抗逆性的目的。表 5 ,参 6。

Hyperspectral Intelligent Monitoring System of Major Soil Nutrients Based on ArcGIS Engine

Based on the object-oriented concept,the hyperspectral intelligent monitoring system of major soil nutrients was designed and developed by using C# and ArcGIS Engine in combination with Microsoft SQL Server.The system mainly includes the following functions：file operation,basic map operation,spectral preprocessing,model management,nutrient content quick calculation,spatial distribution analysis,user management and so on.This system can accomplish the input and preprocessing of soil hyperspectra,and calculate the content of major nutrients,such as soil organic matter,nitrogen,phosphorus as well as potassium quickly and intelligently based on hyperspectral data.Thereby,the soil nutrients regional distribution in the research area can be analyzed by using the principle of geostatistics.This study can not only promote the practicability of soil quantitative remote sensing,but also provide references for the decision-making of agricultural fertilizing.

Genotypic Differences in Grain Yield and Physiological Nitrogen Use Efficiency Among Rice Cultivars

Efficient use of N in agricultural practice can increase yield, decrease production costs and reduce the risk of environmental pollution. Effects of N fertilizer application rates on grain yield and physiological N use efficiency (PE) in relation to the accumulation and redistribution of biomass and N in rice (Oryza sativa L.) cultivars were studied at two experimental farms of Nanjing Agricultural University, Nanjing, China in 2004. Three high N use efficiency (NUE) rice cultivars (Wuyunjing 7, Nanguang and 4007) and one low NUE rice cultivar (Elio) with similar growth patterns were studied under seven N rates (0, 60, 120, 180, 240, 300 and 360 kg ha -1 ). Grain yield increased with the N application rate and attained plateau at 180 kg N ha -1 for rice cultivars at each site. Increasing N rate decreased PE for biomass and grain yield. Grain yield and PE of Elio were about 20% and 18% lower than those of high NUE cultivars. Differences in biomass, N accumulation and N redistribution were observed at the post-heading stage among rice cultivars with differing NUEs. The less reproductive tillers of Elio resulted in less demand for C and N during grain filling, thus leading to lower PE of Elio compared with the high NUE rice cultivars.

Nutrient Cycling and Balance in Red Soil Agroecosystem and Their Management

An experiment was conducted in a red soil derived from Quaternary red clay in the Ecological ExperimentStation of Red Soil, the Chinese Academy of Sciences, located in Yingtan (28° 15′ 30″ N, 116° 55′ 30″E), Jiangxi Province. The results show that the major ways of nutrient loss are leaching and nitrogenvolatilization. Rationalizing crop distribution, stimulating nutrient recycling, and improving internal nutrientflow are effective measures to decrease nutrient loss and to promote nutrient utilization efficiency. Theimportant ways of regulating nutrient cycling and balance in the agroecosystem of the red soil are to establishoptimal eco-agricultural models, practice balanced fertilization and combine the cropping system with thelivestock system.

Effects of Agricultural Practices on Soil Organic Nitrogen Fractions in an Inceptisol of a Cocoa Plantation

The effect of agricultural practices on soil organic nitrogen （N） fractions in a cocoa plantation has not been much revealed till now. Despite the fact that soil organic N has been long admitted for its importance to maintain soil fertility. Presented field experiment was conducted in Kaliwining Experimental Station, Indonesian Coffee and Cocoa Research Institute （ICCRI）, Jember, East Java, Indonesia, to investigate the effect of cocoa farm management, namely fertilization, weeding and soil tillage on the content of soil organic N fractions. The design of experiment was arranged in a split-split plot with two levels of weeding as main plots, two levels of soil tillage as subplot and three different fertilizer treatments as sub-sub plot. The analysis of soil N including total N and soil organic N fractions, namely, total hydrolized N, ammonium N, amino sugar N and amino acid N, were performed. The result showed that the effect of fertilization treatment was significant to the content of total N, ammonium N, amino sugar N and amino acid N. No-tillage treatment resulted in total N and amino sugar-N content increasing by 8% and 24%, respectively, over tillage treatment. Slashing treatment caused increase of the total N by 3% from herbicide treatment, whilst decrease of ammonium N and amino sugar N by 7% and 24%, respectively.

GIS-Supported Precision Agricultural Fertilization Management at Small Scale

Precision agricultural fertilization technique at small scale is the key for regional cultivated land protection and management. Taking Dingzhuang Town (located in Guangrao County, Shandong Province) as a case study, this article explores the precision agricultural fertilization technique at small scale. First, three main cropping systems are identified via field investigation, namely "wheat–maize–soybean", "garlic–maize" and "cotton". Then, application amount of fertilizer N, P and K under the three cropping systems is calculated on the parameters acquired through field experiment, using nutrient balance approach on the support of geographic information system technique. The results indicate that, precision agricultural fertilization technique at small scale take on different characteristics compared with that at larger scale. The spatial distribution of soil nutrients in Dingzhuang Town is out of equilibrium, and huge amount fertilizer is needed to satisfy local agricultural production. There is huge distinction of fertilizer ap- plication amount under different cropping systems. The demand of fertilizer amount under "wheat–maize–soybean" system is larger than that under "garlic–maize" and "cotton" systems. This study can provide theories and principles for regional precision agricul- tural fertilization management.

Dissolved Organic Nitrogen Leaching from Rice-Wheat Rotated Agroecosystem in Southern China

The rice-wheat rotation in southern China is characterized by frequent flooding-draining water regime and heavy nitrogen(N)fertilization. There is a substantial lack of studies into the behavior of dissolved organic nitrogen(DON) in the intensively managed agroecosystem. A 3-year in situ field experiment was conducted to determine DON leaching and its seasonal and yearly variations as affected by fertilization, irrigation and precipitation over 6 consecutive rice/wheat seasons. Under the conventional N practice(300kg N ha-1for rice and 200 kg N ha-1for wheat), the seasonal average DON concentrations in leachate(100 cm soil depth) for the three rice and wheat seasons were 0.6–1.1 and 0.1–2.3 mg N L-1, respectively. The cumulative DON leaching was estimated to be1.1–2.3 kg N ha-1for the rice seasons and 0.01–1.3 kg N ha-1for the wheat seasons, with an annual total of 1.1–3.6 kg N ha-1. In the rice seasons, N fertilizer had little effect(P > 0.05) on DON leaching; precipitation and irrigation imported 3.6–9.1 kg N ha-1of DON, which may thus conceal the fertilization effect on DON. In the wheat seasons, N fertilization had a positive effect(P < 0.01)on DON. Nevertheless, this promotive effect was strongly influenced by variable precipitation, which also carried 1.8–2.9 kg N ha-1of DON into fields. Despite a very small proportion to chemical N applied and large variations driven by water regime, DON leaching is necessarily involved in the integrated field N budget in the rice-wheat rotation due to its relatively greater amount compared to other natural ecosystems.