Current Situation and Prospect Analysis of Biogas Project in Scale Farms in Chengdu

In order to implement National Sustainable Development of Agriculture 2015-2030 and supply-side reform of agriculture, and seek the way to replace chemical fertilizer by livestock and poultry manure, the animal breeding scale and the demand space for biogas project were analyzed according to the changes in farm scale and farm quantity, the present situation of livestock breeding, the biogas technical pattern and present project quantity in Chengdu. Furthermore, based on the cultivated land area in Chengdu, a principle that ＂land decides production, pro- duction decides fertilizer, and fertilizer decides livestock＂ was proposed, and a pro- gram for the livestock quantity and biogas projects in Chengdu in ＂The 13th Five- Year＂ was suggested. Suggestions were also made for government to modify the allowance standards for biogas project construction.

Utilization Survey of Livestock Manure Resources in Large-scale Farms of Yangzhou

Based on surveying the conditions of large -scale farms and commercial manure in the each county of Yangzhou city, the situations and problems for utilization of livestock manure resources were grasped. After an analysis of the potential value of livestock manure, the suggestion and strategy for utilization of livestock manure resources were proposed based on the actual conditions in Yangzhou city.

Efficiency Comparison and Influencing Factor Analysis of Dairy Farms over/at Different Scales:Based on the Survey Data of 263 Scale Farms in 22 Provinces of China

China's dairy farming has presented a striking development in recent years.Under the dual constraints of environment and resources,it is of practical significance to increase the output of dairy farming and ensure the healthy and stable development of the dairy industry,by accurately comparing the differences in the farming efficiency of dairy farms at different scales and grasping key factors influencing the farming efficiency.This study,through the cost analysis of 263 scale farms across 23 provinces and regions of China in 2019,reaches a result that the cost of a single cow in a certain scale farm increases with the enlargement of the scale,and shows an inverted-U shaped curve with the relatively large scales(1001-2000 cows)at the highest point.It measures the farming efficiency of dairy farms at different scales through the data envelopment analysis and finds that the scale efficiency and allocation efficiency of scale farms in China are relatively high,while the technology efficiency and cost efficiency are relatively low.The efficiency of different scale farms is obviously different,where the cost efficiency,allocation efficiency and scale efficiency show a U-shaped curve as the scale enlarges(with the relatively large scale as the lowest point),while the technology efficiency gradually decreases as the scale expands.It is concluded that for the scale farms,feed conversion ratio and forage-to-concentrate ratio have a significantly negative impact on the scale efficiency,while the labor cost,number of employees,and depreciation of fixed assets are negatively correlated to the technology efficiency and cost efficiency of dairy farming.

Sustainable Intensification of Cultivated Land Use and Its Influencing Factors at the Farming Household Scale: A Case Study of Shandong Province, China

Promoting the sustainable intensification of cultivated land use(SICL) has become crucial for ensuring a sufficient supply of grain and important agricultural products, as well as for the sustainable use of resources. Taking widely used areas of Shandong Province in China as examples, an analytical scale and level framework for SICL is constructed in this study. It measures the level of SICL through material flow analysis, constructs Tobit models to analyze the influencing factors of SICL at the farming household scale,and analyzes the transition mechanisms of SICL. The results show that the overall level of SICL in Shandong Province is low, and the spatial distribution is uneven. There are relatively more farmers participating in unsustainable intensification than in medium or low levels of SICL, with farmers working at a high level of SICL making up the smallest proportion. The factors that determine the level of SICL at which farmers work vary significantly. More male farmers operate at a low SICL level than female farmers, while females outnumber males at a high SICL level. This is mainly related to the regional distribution of age and population. Meanwhile, with larger cultivated land areas, there is a lower degree of land fragmentation, with a higher level of SICL corresponding to a smaller distance to the nearest town closer within 1–5 km from the town center. We can see the level of SICL and its processes themselves are closely related to time and space scales. Based on the above analysis, it is necessary to clarify the standard processes of SICL to adapt them to local conditions. This includes instructing managers on how to improve resource utilization, increase the sustainable development of cultivated land and establish a comprehensively efficient and functional SICL mechanism. The sustainable intensification of cultivated land use and its specific application in the new era are conducive to enriching the frontier theories and methodology of sustainable development, and are of great significance to the advancement of green agriculture and the decision-making of rural high-quality development.

Land Distribution and Economic Development： Small Scale Agriculture in Developing Countries

Small scale farmers constitute about half of world＇s hungry people and include three quarters of Africa＇s malnourished children. The appropriate identification and characterization of this population and the constraints it faces are essential for the design and the successful implementation of safety nets and to properly target their needs and effectively include them in agricultural development strategies. This paper aims at exploring the characteristics, limitations, and potential for agricultural development of small scale farmers in developing countries. It calculates four land cultivated thresholds which are then used as a measure to classify households that were surveyed in four developing countries. It empirically estimates the magnitudes of the smallholders, their characteristics, as well as their poverty status using the four thresholds. This analysis provides empirical evidence that small scale farmers still prevail in terms of population distribution in rural area settings in developing countries. Small scale farmers heavily rely on farm income as their form of livelihood and heavily contribute to the rural income. It also finds that land is unequally distributed among small and large scale farmers in the rural households. Small scale farmers also have the highest poverty rates in these rural settings.

Risk preferences and the low-carbon agricultural technology adoption:Evidence from rice production in China

Climate change which is mainly caused by carbon emissions is a global problem affecting the economic development and well-being of human society.Low-carbon agriculture is of particular significance in slowing down global warming and reaching the goal of“carbon peak and carbon neutrality”.Therefore,taking straw incorporation as an example,this paper aims to investigate the impact of risk preferences on farmers’low-carbon agricultural technology(LCAT)adoption.Based on a two-phase micro-survey data of 1038 rice farmers in Jiangsu,Jiangxi,and Hunan provinces,this paper uses experimental economics methods to measure farmers’risk aversion and loss aversion to obtain the real risk preferences information of the farmers.We also explore the data to examine the actual LCAT adoption behavior of farmers.The results revealed that both risk aversion and loss aversion significantly inhibit farmers’LCAT adoption:more risk-averse or more loss-averse farmers are less likely to adopt LCAT.It is further found that crop insurance,farm scale and governmental regulations can alleviate the negative impact of risk aversion and loss aversion on farmers’LCAT adoption.Therefore,we propose that local governments need to promote low-carbon agricultural development by propagating the benefits of LCAT,extending crop insurance,promoting appropriate scale operations,and strengthening governmental regulations to promote farmers’LCAT adoption.

Diagnosis of Mixed Infection of CSFV, PRV and E.coli in a Modern Pig Farm of Guizhou Province

In order to understand the incidence reasons in a scaled pig farm of Guizhou Province, the infected pigs were diagnosed with epidemiological investigation, clinical observation, pathological diagnosis, enzyme-linked immunosorbent assay （ELISA）, PCR/RT-PCR and bacterial isolation and identification. The results showed that the pigs were infected mixedly with classical swine fever virus （CSFV）, pseudorabies virus （PRV） and E. coli. Therefore, some measures should be adopted to control the incidence of CSF, PR and colibacillosis in the pig farm.

The relationship between farm size and fertilizer use efficiency:Evidence from China

Low fertilizer use efficiency is commonly found in China’s agriculture sector. It is critical to understand the drivers of fertilizer use in order to increase fertilizer use efficiency(FUE). The purpose of this paper is to investigate the relationship between farm size and FUE based on farm-level data in China. The results suggest a positive farm size–FUE relationship. The estimated elasticities of farm size for rice, maize, wheat–maize, and rice–maize are similar, and the average elasticity of farm size is around 0.2. Statistically, a 1% increase in farm size is associated with a 0.2%increase in FUE. The positive effect of farm size on FUE is not due to the increase in yield, but the reduction in fertilizer use while keeping yield largely unchanged. The findings suggest that promoting the expansion of farm size may increase FUE, and thus reduce environmental pollution caused by fertilizer overuse.

Pathogenicity of Escherichia coli O_(123) from Rex Rabbit on White Mice

[Objective]The paper was to analyze the pathogenesis of Escherichia coli O123 from rex rabbit. [Method]E. coli O123 isolated from rabbit liver with diarrhea symptom in scale rex rabbit farm was intraperitoneally injected into 18- 22 g Kunming mice,and its pathogenicity was determined by clinical symptoms and pathological examination. [Result]When the inoculation concentration was about 8. 5 × 107 CFU /mL,Kunming mice appeared the clinical symptoms of drooping spirit,diarrhea and gathering,and the mortality reached 50%. Anatomical examination found that intestinal wall was thinning and intestinal mucosa was bleeding. [Conclusion]E. coli from rex rabbit has strong pathogenicity,and establishing animal model with Kunming mice to study its pathogenesis is of great reference significance for diagnosis and prevention of E. coli disease of rex rabbit.

CRITICAL PROCESSES AND MAJOR FACTORS THAT DRIVE NITROGEN TRANSPORT FROM FARMLAND TO SURFACE WATER BODIES

Agricultural non-point source pollution is increasingly an important issue affecting surface water quality.Currently,the majority of the studies on nitrogen loss have focused on the agricultural field scale,however,the response of surface water quality at the watershed scale into the nitrogen loss at the field scale is poorly understood.The present study systematically reviewed the critical processes and major factors that nitrogen transport from farm fields to surface water bodies.The critical processes of farmland nitrogen entering surface water bodies involve the processes of nitrogen transport from farmland to ditches and the transformation processes of nitrogen during migration in ditches/rivers.Nitrogen transport from farmland to ditches is one of the prerequisites and critical processes for farmland nitrogen transport to surface water bodies.The transformation of nitrogen forms in ditches/rivers is an intermediate process in the migration of nitrogen from farmland to surface water bodies.Nitrogen loss from farmland is related to soil storage and exogenous inputs.Therefore,nitrogen input management should not only consider the current input,but also the contribution of soil storage due to the historical surpluses.Ditches/rivers have a strong retention capacity for nitrogen,which will significantly affect the process of farmland nitrogen entering surface water bodies.The factors affecting nitrogen transformation in river/ditches can be placed in four categories:(1)factors affecting hydraulic retention time,(2)factors affecting contact area,(3)factors affecting biological activity,and(4)forms and amount of nitrogen loading to river/ditches.Ditch systems are more biologically(including plants and microbes)active than rivers with biological factors having a greater influence on nitrogen transformation.When developing pollution prevention and control strategies,ecological ditches can be constructed to increase biological activity and reduce the amount of surplus nitrogen entering the water body.The present research should be valuable for the evaluation of environment impacts of nitrogen loss and the non-point source pollution control.