Empirical analysis on the influence of the Shaanxi fruit industry on regional food security

As part of its development policy to relieve rural poverty in west China, the Chinese government has introduced measures such as agricultural tax exemptions, agricultural subsidies, and scientific, technological and restructuring improvements to agriculture. Following these actions, farmers’ incomes have increased greatly and the economy in poor areas of west China has seen rapid improvements. However, agricultural restructuring, infrastructure construction and ecological restoration projects have reduced the area of land under arable farming, restricting opportunities for increasing total grain yield. Regional food security is therefore threatened and an imbalance between economic development and food security is created. Shaanxi is a representative province in west China where agricultural restructuring has resulted in large areas of arable land being converted into orchards that produce higher economic returns. This study randomly surveyed 1430 farm households in three counties in the apple-producing region of Shaanxi Province (Luochuan, Changwu and Baishui). The standard of living and household income of farmers in the fruit production areas were higher than in grain-producing areas, thus discouraging grain production. Land under agriculture in the counties studied comprised 59% orchards and 39% arable, with 2% under other uses. Per capita, 204.3 kg of grain was produced, 51% of that required for self-sufficiency. Other staple foods produced amounted to only 13.9% of that needed for self-sufficiency. As a result, nearly half of the grain needed by the community was purchased from outside, resulting in very poor regional food security. Clearly, fruit production in this region seriously affects regional food security. Coordination of relationships between rural economic development and regional food security is key for sustainable development of the regional agriculture and economy of west China.     

Performance of a water hyacinth （Eichhornia crassipes） system in the treatment of wastewater from a duck farm and the effects of using water hyacinth as duck feed

Nowadays, intensive breeding of poultry and livestock of large scale has made the treatment of its waste and wastewater an urgent environmental issue, which motivated this study. A wetland of 688 m2 was constructed on an egg duck farm, and water hyacinth (Eichhornia crassipes) was chosen as an aquatic plant for the wetland and used as food for duck production. The objectives of this study were to test the role of water hyacinth in purifying nutrient-rich wastewater and its effects on the ducks’ feed intake, egg laying performance and egg quality. This paper shows that the constructed wetland removed as much as 64.44% of chemical oxygen demand (COD), 21.78% of total nitrogen (TN) and 23.02% of total phosphorus (TP). Both dissolved oxygen (DO) and the transparency of the wastewater were remarkably improved, with its transparency 2.5 times higher than that of the untreated wastewater. After the ducks were fed with water hyacinth, the average daily feed intake and the egg-laying ratio in the test group were 5.86% and 9.79% higher, respectively, than in the control group; the di erences were both significant at the 0.01 probability level. The egg weight in the test group was 2.36% higher than in the control group (P < 0.05), but the feed conversion ratios were almost the same. The eggshell thickness and strength were among the egg qualities significantly increased in ducks fed with water hyacinth.We concluded that a water hyacinth system was e ective for purifying wastewater from an intensive duck farm during the water hyacinth growing season, as harvested water hyacinth had an excellent performance as duck feed. We also discussed the limitations of the experiment.     

Impacts of the Rising Opportunity Cost of Farm Labor on Agricultural Land Use Structure: Theory and Empirical Evidences

Abstract

Nowadays the rising of opportunity cost of farm labor comes to the forefront of attention in China. In order to understand its impact on agricultural land-use structure, a theoretical framework of household economics is formulated drawn on Low’s model. Under the theoretical framework, the impact of the rising opportunity cost of on-farm on cropping structure is deduced in theory. And then, using statistic and survey data, taking mountain area of southern Ningxia as an example, the theoretical assumes are verified. The results show that the rise of opportunity cost of farm labor leads to less diversified cropping structure.     

基于在线观测本地因子的长三角家禽养殖氨排放时空分布特征

为获取长三角地区家禽养殖氨排放因子和时空分布特征,通过在线高分辨率监测系统对典型规模化蛋鸡养殖场棚舍养殖和粪便堆肥环节的氨浓度进行连续监测,获取不同季节、不同生长阶段的氨浓度和排放因子,并建立基于本地化排放因子的长三角家禽养殖氨排放清单.结果表明,棚舍养殖和粪便堆肥环节春夏秋冬4个季节ρ（NH₃）日均值分别为：（1.85±0.38）、（4.58±0.33）、（3.87±0.12）、（2.83±0.47）mg·m^-3和（2.04±0.50）、（4.04±1.04）、（2.51±0.67）、（1.55±0.16）mg·m^-3,氨浓度呈显著的日小时变化趋势,养殖棚舍春夏秋冬小时ρ（NH₃）最大值出现在中午13:00～14:00,最小值出现在凌晨01:00～03:00,粪便堆肥环节夏秋季节的小时ρ（NH₃）最大值出现在16:00～19:00,春冬季的日小时变化过程则不明显;氨日小时浓度变化主要受日温度变化、畜禽活动和清粪管理等因素影响.蛋鸡不同生长阶段的氨浓度呈显著差异,青年鸡、产蛋鸡...     

区域农村土地市场发育的农户行为响应与农业土地利用变化——以江苏省苏州市、南京市、扬州市村庄及农户调查为例

在江苏省苏州市、南京市、扬州市各自选择了2个村的基础上,运用对240个农户的抽样调查资料,建立了区域农业土地利用变化分析的数量经济模型,较为深入地分析了农村土地流转市场引导下的农户行为对于农业土地利用变化的影响。研究结果表明,在农户决策行为起主导作用的前提下,农业土地利用正在逐步由传统的大田作物向效益更高的经济作物和水产养殖等地类转化;农户家庭非农就业水平的提高有效地推进了这一转化;同时,农户受教育水平的高低以及政府行为都在一定程度上影响着农业土地利用变化。最后从区域非农产业和城镇化发展、深化农村土地产权的物权化改革、农村社会保障制度的完善、建立农村土地流转中介机制、进一步规范政府行为及积极推进农村户籍制度改革等方面提出了一些政策性建议。     

Genetic Engineering in Agriculture: Who Stands to Benefit?

The use of genetic engineering inagriculture has been the source of much debate. Todate, arguments have focused most strongly on thepotential human health risks, the flow of geneticmaterial to related species, and ecologicalconsequences. Little attention appears to have beengiven to a more fundamental concern, namely, who willbe the beneficiaries of this technology? Given the prevalence of chronic hunger and thestark economics of farming, it is arguable thatfarmers and the hungry should be the mainbeneficiaries of agricultural research. However, theapplication of genetic engineering appears unlikely tobenefit either of these two groups. This technology islargely controlled by the private sector, and itscontinued development hinges on its profitability.Thus, the only likely beneficiaries of the applicationof genetic engineering in agriculture are companieswith the capacity to use it.     

农田生态系统管理与非点源污染控制

随着化肥和农药大量使用,农业非点源污染已经成为全球水污染的主要来源．不同农田管理措施,如免耕、少耕、传统耕作方式,化肥和农药的使用量、使用方式以及使用季节,灌溉的不同方式,如沟灌、淹灌和喷灌等与农业非点源污染形成之间均有密切的关系,通过农田景观设计来控制非点源污染,可望在控制农业非点源污染方面起到指导作用．     

退耕还林还草对土地利用变化影响程度研究——以延安生态建设示范区为例

文章在分析延安生态建设示范区2000-2003年间各土地利用类型的数量变化和空间特征的基础上,引入退耕指数、退耕影响系数等指标研究退耕还林草对示范区土地利用结构变化的影响。结果显示,示范区已退耕坡耕地36.07%,平均每年退耕12.02%,全区的退耕影响系数高达4.76,该结果表明大规模的退耕还林草活动对区域土地利用变化的影响很大,它推动了土地利用结构的优化。分乡镇的研究显示,退耕对示范区各乡镇土地利用变化的影响存在一定的差异,除2个乡镇的退耕影响系数远远低于全区平均水平外,其他7个乡镇都高于全区平均水平。     

Imazaquin degradation and metabolism in a sandy loam soil amended with farm litters

Irnazaquin applied in legume crops has a long residual time in soil, which often impacts safety of the susceptible crops. To increase safety of imazaquin application, two composted litters, bovine manure （BM） and chicken manure （CM）, were used to determine their effects on imazaquin environmental behavior by incorporating each kind of manure into the tested sandy loam soil at 10% （w/w）. The degradation of imazaquin in BM- and CM-amended soil was about 2.4 and 1.5 times, respectively, faster than that in unamended soil. The half-lives of imazaquin in BM-amended soil varied between 6.7 and 15.4 d over the temperature range of 20 to 40℃, and the degradation rate constant （k） increased by a factor of about 1.5 for every 10℃ change. Higher mix ratio did not significantly increase the degradation, and the optimal active degradation of imazaquin was observed approximately at the mix ratio of 10：1 of soil to BM. The different moisture levels had negligible effect on imazaquin degradation. In both unamended and BM-amended treatments, two metabolites were observed at 5, 10 and 30 d after treatment. One metabolite at retention time （RT） of 8.4 rain was identified as 2-（4- hydroxyl-5-oxo-2-imidazolin-2-yl） quinoline acid, originating from the loss of isopropyl group and hydroxylation at the 4-position of imidazolinone ring. The other at RT of 12.9 rain was identified as quinoline-2,3-dicarboxylic anhydride, resulting from detachment of imidazolinone ring and the forming of dicarboxylic anhydride. This finding suggested that the addition of farm litters into soil might be a good management option since it can not only increase soil fertility but also contribute to increase safety of imazaquin application to the following susceptible crops.     

城市污水厂二级生物处理出水氯消毒影响因素研究

进行了城市污水厂二级生物处理出水氯消毒影响因素研究,结果表明:对次氯酸钠,二氧化氯消毒效果影响最大的是pH,其次是有机氮,COD,氨氮的影响相对较小。运用Selleck-Collins公式对数据进行分析。