通过2年定位试验研究不同玉米-豆科间套作模式下（玉米-大豆带状套作、玉米-花生带状间作、玉米净作、大豆净作和花生净作）作物氮素吸收与根系分布、豆科结瘤和土壤氮素有效性之间的关系。结果表明：与净作相比，间套作显著降低了单季作物的单位面积吸氮量，但玉米-大豆套作和玉米-花生间作的系统总吸氮量分别增加31.7-45.4%和7.4-12.2%。间套作显著增加了玉米和大豆的单株氮素吸收量，与净作相比分别增加61.6%和31.8%，间作花生的单株吸氮量较净作降低46.6%。间套作系统中玉米和大豆的根系呈现不对称性分布，其根长密度和根表面密度显著高于相应单作。间作花生受竞争抑制，其根表面密度显著低于相应单作。与净作相比，套作大豆的根瘤数量和根瘤鲜重显著增加，间作花生根瘤数和根瘤鲜重则显著降低。间套作显著提高了玉米和大豆的土壤酶活性（蛋白酶、脲酶、硝酸还原酶）和土壤有效氮含量，但降低了花生的土壤酶和土壤有效氮含量。玉米-大豆带状套作系统比玉米-花生带状间作系统更有利于氮素吸收，玉米与豆科间套作可以促进玉米对氮素的吸收，从而降低氮肥用量，提高农业可持续性。

    To study the correlation of broiler chickens with energy intake, growth and mitochondrial function which exposed to sustained cold and heat stress and to find out the comfortable temperature, 288 broiler chickens (21-day with (748±26) g, 144 males and 144 females) were divided randomly into six temperature-controlled chambers. Each chamber contained six cages including eight AA broilers per cage, each cage as a repeat. After acclimation for one week (temperature, 21°C; relative humidity, 60%), the temperature of each chamber was adjusted (finished within 1 h) respectively to 10, 14, 18, 22, 26, or 30°C (RH, 60%) for a 14-day experimental period. After treatment, gross energy intake (GEI), metabolizable energy intake (MEI), the ratio of MEI/BW, metabolizability, average daily gain (ADG), the concentration of liver mitochondria protein and cytochrome c oxidase (CCO) were measured respectively. Our results confirmed that when the temperature over 26°C for 14 days, GEI, MEI and CCO activities were decreased significantly (P<0.05), but the concentration of liver mitochondria protein was increased and metabolizability of broilers was not influenced (P>0.05). Compared with treatment for 14 days, the ratio of MEI/body weight (BW) were also decreased when the temperature over 26°C after temperature stress for 7 days (P<0.05), meanwhile mitochondrial protein concentration was increased at 10°C and CCO activity was not affected (P>0.05). Additionally at 22°C, the ADG reached the maximal value. When kept in uncomfortable temperatures for a long time, the ADG and CCO activities of broiler were reduced, which was accompanied by mitochondrial hyperplasia. In summary, our study focused on the performance of broilers during sustained cold and heat environmental temperatures ranging from 10 to 30°C. From the point of view of energy utilization, moreover, 22 to 26°C is comfortable for 28–42 days broilers. And these could provide the theoretical basis on the high efficient production.

This article analyses the technical and environmental efficiency of hog production in China using data from the China Agricultural Product Cost-Benefit Compilation (NDRC 2005–2013) and the First National Census of Pollution: Manual of Discharge Coefficient of Livestock and Poultry Industry (IEDA and NIES 2009). The empirical results show a great variation in environmental efficiency, ranging from 0.344 to 0.973 with a mean value of 0.672 that declines over time. Southwest China is found to be the most environmentally efficient region, while the Northeast and the Northwest are the least efficient. Another finding is that technical and environmental efficiencies are highly correlated in hog production; the most environmentally efficient regions are usually found to have high technical efficiency, and vice versa. In addition, we computed the output elasticities with respect to each factor input. The results show that feed is the most efficient input, with an output elasticity of approximately 0.551, which is much higher than the elasticity of the nitrogen surplus, other capital or labour. The output elasticity with respect to the nitrogen surplus is 0.287 on average. Finally, the scale elasticity in hog production is slightly higher than 1.

China’s hog production is undergoing a great transformation due to the soaring demand and changing raising system. Regarding the essential role of pork in Chinese diet, a systematic analysis on the productivity and efficiency of hog production can provide significant implications for policy makers. This paper investigates the productivity and efficiency of hog production and the determinants of technical efficiency in China using a household level panel data (2004–2010). A stochastic frontier translog production function with scaling property in inefficiency term is adopted for hog production analysis, and the determinants of technical efficiency are incorporated in a one-step estimation using maximum likelihood estimation. Our results show that the average technical efficiency of hog production in China is 0.5914. More importantly, we find that specialized farmers have higher technical efficiency than others, and technical efficiency in the eastern region is higher than that in Central and West China.

According to the contemporary ecosystem approach, the linkages of human actions with their environment have to be assessed in an integrative manner. The Driver-Pressure-State-Impact-Response (DPSIR) model is applied to identify and describe processes and interactions in human-environmental systems. An example application from a research project dealing with the development of sustainable management strategies for the agriculture in Jiangsu, China, illustrates the potentials and limitations of its sustainable development. The concept and indicators of ecological integrity are used to assess the indicators in the dimensions of DPSIR between 2003 and 2006. The main drivers included population growth which caused increasing demand for food, growing environmental demands, and rapidly decreasing of land and other natural resources. The main environmental problem was water pollution. The results show that in the dimension of driver, total grain output and agricultural land productivity both increased. Labor intensive agriculture has been promoted to increase agricultural land productivity. In the dimension of pressure, on the positive side, infrastructure got greatly improved, the input level such as total power of machinery, and level of fertilizer use increased, and level of pesticides use decreased, but on the negative side, cultivated land per capita and irrigation rate decreased, natural resources keep decreased. Environmental pollution indicators such as industrial wastewater discharge and acid rain rate increased in Jiangsu Province. In the aspect of state, ecosystem state was improved, plant coverage index increased, biological abundance index increased, fertilizer productivity increased, eco-environmental quality index increased, but land degradation index also increased. In the aspect of impact, output level increased, output efficiency enhanced, farmer’s social economic benefit improved. In the aspect of response, social support was greatly improved, input for environmental governance increased. To assess the effects of environmental governance, Jiangsu government was successful to increase compliance rate of sulfur dioxide emissions, but not so efficient in compliance rate of industrial wastewater discharge.