Investigation on Contact Mechanics Between Soil and Metal

Soil-metal contact interaction is common with machinery operations in agricultural production. In this paper, a method has been proposed to determine the stress-strain relation of soil at soil-metal contact surface with a modified triaxial apparatus, and a constitutive model is developed for numerical analyses of such kind of contact problems.     

Evaluation the potential economic impacts of Taiwanese biomass energy production

The Taiwanese rice paddy land set-aside program diverts a substantial land area. Given today’s high energy prices and interests in energy security, that set-aside area could be converted to produce bioenergy feedstocks. This study evaluates the economic and environmental impacts of such a policy change using a Taiwanese agricultural sector model. The results show that such a strategy provides increased farm revenue, increased rural employment, increased energy sufficiency and reduced greenhouse gas emissions but also increased government expenditures. These outcomes indicate that the agricultural sector could play a positive role by producing renewable energy.     

基于Web的农机零件CAPP系统

简述计算机辅助工艺设计系统CAPP研究的意义及在国内外的研究现状与存在的问题,提出基于Web的农机零件CAPP系统的设计体系结构,介绍系统的各功能模块。     

The PhytO3 Tech Crop Protection Technology – Trial Results in a 2,700 ha (6,500 acre) Soy Farm in Brazil

Extended field trial testing of the PhytO3 technology (applying sequentially and rapidly electrolyzed water, ozone in water, and UV-C radiation to control insects and replace chemical sprays) was conducted in Brazil on growing soy bean crops during December 2006 to March 2007. Despite the very poor growing conditions because of excessive rainfalls, the test crops all reached harvest and provided significant economic benefits to the farmer. Details of the testing program are described. In addition to eliminating the need for pesticides and insecticides, crops treated by the PhytO3 technology qualify as organic-grown crops, and therefore command about double prices on world markets.     

Soil and leaf nutrient interactions following application of calcium silicate slag to sugarcane

In certain areas of the Everglades Agricultural Area, plant and ratoon sugarcane (Saccharum L.) yields are increased by application of Si from calcium silicate slag. The greatest yield responses are obtained in the plant crop the first year after application of slag and when plant uptake of Si is increased. Magnesium deficiencies have been reported after slag application. The objective of this study was to quantify interactions of soil and leaf nutrients on sugarcane grown on a Terra Ceia muck (Euic, hyperthermic Typic Medisaprist) that had previously received calcium silicate slag. Slag was applied at five rates, and yields were evaluated from plant, first-ratoon, and second-ratoon (stubble) crops at two locations. Soil and leaf from each crop were sampled for nutrient analysis and the results were used to interpret the yield data. Although slag increased cane yield by as much as 39% and sugar yield by 50%, for each 100 mg L^–1 drop in extractable soil Mg, cane yields declined by 5.3 Mg ha^–1 and sugar yields by 0.9 Mg ha^–1. At leaf Si concentrations exceeding 10 g kg^–1, optimum cane and sugar yields were observed, while leaf Mg concentrations approached critical leaf concentrations below 1.5 g kg^–1. Estimates of total leaf nutrient uptake during each crop indicated that uptake of Mg did not meet nutrient demands at high biomass production. Nutrient antagonism between Si and Mg is suggested. Low soil Mg may contribute to the marked crop responses to slag and for the decline in stubble production. Application of a magnesium fertilizer may be necessary to maintain high nutrient availability.Contribution from the University of Florida, Institute of Food and Agricultural Sciences. Florida Agric. Exp. Stn., Journal Series no. R-00859.     

Effects of Spraying Ozonated Water on the Severity of Powdery Mildew Infection on Cucumber Leaves

Effects of spraying ozonated water on the severity of powdery mildew infection, visible disorder/injury occurrence, and net photosynthesis in cucumbers were investigated. The severity in the ozonated water treatment was contained to almost the same level throughout the 14-day period of the experiment, while the severity steadily increased in the non-treated control and distilled water treatment. Neither visible disorder/injury on the leaves nor a large difference in net photosynthesis between before and after spraying the ozonated water was observed. The results indicate that ozonated water can be at least a partial alternative to agricultural chemical fungicides for powdery mildew on cucumber leaves.     

Exploration of the land potential for the production of biomass for energy in the Netherlands

The energy potential for energy crops and biomass residues in the Netherlands is assessed. The analysis explores the possible use of land for biomass production in the future. Various government memorandums and analyses of the expected future land use in various sectors have served as the basis for the assessment of the supply of and the demand for land in the future. In this study the potential supply of agricultural land is based on expected productivity increments in agriculture and assumptions with respect to the future demand for agricultural products. Various future claims for infrastructure, forestry, urban areas and nature are subtracted from the expected supply. The net projected supply of land ranges from zero to 52 000 ha in 2000 to 110 000-250 000 ha in 2015. The supply of agricultural land depends however on a number of supra-national factors, such as the European agricultural policy, world market developments and the agricultural production in the countries in Eastern Europe. Uncertainties remain, therefore, and the projected supply of agricultural land should be considered as a possible scenario based on current trends. If the calculated land potential is used for energy crops like miscanthus and short rotation coppice, this land could contribute 0-10 PJ in 2000 and 27-59 PJ in 2015. Secondary biomass yields, such as those from forestry, agricultural residues, wood from prunings, etc., could contribute a further 34 PJ in 2000, decreasing to approximately 28 PJ in 2015. Taken together these potentials could satisfy 1-1.5% of the energy requirements of the Netherlands in 2000 and 1.5-2.5% in 2015, provided that energy farming is an economically feasible activity for farmers.     

A dual-probe approach for evaluation of gypsum crystallization in response to antiscalant treatment

An experimental system was developed to assess and rank the performance of commercial antiscalants designed to inhibit mineral scale formation on reverse osmosis membrane surfaces. The study focused on calcium sulfate dihydrate (gypsum) precipitation to illustrate an approach to antiscalant ranking based on its ability to retard the observed onset (i.e., induction time) of gypsum crystallization from supersaturated solutions. The experimental method consisted of on-line monitoring solution turbidity rise and calcium ion concentration decline to signal the onset of gypsum crystallization. Significant differences were found among commercial antiscalants with respect to achievable levels of induction time retardation. Moreover, antiscalant effectiveness with respect to dosage also varied significantly among antiscalants. The present approach enables a relatively simple and robust initial screening of candidate antiscalants based on their induction time as a function of the applied dose.     

宁波市农民收入的现状及增收途径分析

本在宁波农民收入现状分析的基础上，针对现实特点从减少农民、提高劳动素质、加大对农业投资、采取各种农业产业化模式，以及建立和完善社会保障体系五个方面探索了提高农民收入的途径。     

A techno-economic evaluation of biomass briquetting in India

A financial analysis of biomass briquetting technology in India has been undertaken. Simple cost functions for briquetting machines have been developed. Unit cost of briquette production for various types of raw materials and different capacities of briquetting units have been calculated. Role of different factors affecting the cost of production of briquettes have also been analysed.