Supervisor(s): Ministry of Agriculture Sponsor(s): Chinese Academy of Agricultural Sciences；Chinese Association of Agricultural Science Societies CN：11-1328/S
Scientia Agricultura Sinica, the 1st in Comprehensive Agricultural Science, is supervised by Ministry of Agriculture of PRC, and sponsored by Chinese Academy of Agricultural Sciences; Chinese Association of Agricultural Science Societies. Scientia Agricultura Sinica, launched in 1960, is a leading peer-reviewed and mufti-disciplinary journal and published semi-monthly in Chinese with English title, abstract, figures, tables and references. It aims to publish those papers that are influential and will significantly advance scientific understanding in agriculture fields worldwide. The scope covers Crop Genetics, Breeding, Germplasm Resources; Physiology, Biochemistry, Cultivation, Tillage Plant Protection; Soil & Fertilization, Agro-Ecology & Environment, Bio-energy; Animal Science, Veterinary Science, Agricultural Information Science; Food Science; Agricultural Economics and Management; Agricultural Sustainability.
The journal is included in JST, CA and CSCD.
Editor-in-Chief Wan Jianmin Associate Editor-in-Chief Zou Ruicang Tang HuaJun Wu Kongming Guo YuYuan Geng Xu Sun Tan Executive Editor Lu Wenru
[Objective] Under the background of turning crop to forage and adjustment of plantation structure, the study on yield gap of alfalfa, ryegrass and oat grass is crucial for revealing yield potential. It can also provide a scientific basis for making high-yield and high-efficiency forage management strategies. [Method] The publications were collected by searching China National Knowledge Infrastructure and Web of Science with the keywords of “Alfalfa yield, Fertilizer”, “Ryegrass yield, Fertilizer”, “Oat grass yield, Fertilizer”, “Forage planting technology”, “Alfalfa, Fertilizer, China”, “Alfalfa, Irrigation, China”. A total of 176 published references were collected, including 101 articles for alfalfa, 51 articles for ryegrass and 24 articles for oat grass. This study summarized the yield potential and yield gap for three major cultivated forage species in China. Meta-analysis method was carried out to quantify the effects of fertilization, sowing rate and irrigation rate on the yields of three main cultivated forage species. This paper made a preliminary illustration about the factors that affected yield gap and ways to close the yield gap. [Result] The yield potential was 24 t·hm
−2 for alfalfa, 26 t·hm
−2 for ryegrass and 22 t·hm
−2 for oat grass. The farmer’s average yields of alfalfa, ryegrass and oat grass were 28%, 63% and 41%, respectively, of the yield potential. The fertilizer application rate of N(N) and phosphorus (P
2O
5), sowing rate and irrigation rate significantly affected the forage yield. The optimized N and P
2O
5 application rates were 52 and 141 kg·hm
−2 for alfalfa, 585 and 46 kg·hm
−2 for ryegrass. For oat grass, the optimal N fertilizer application rate was not clear, but within the total amount of 225 kg·hm
−2, the oat grass yield increased linearly with the increasing of N application rate. The optimal P
2O
5 application rate was 128 kg·hm
−2 for oat grass. The optimized sowing rate was 20 kg·hm
−2 for alfalfa, 30 kg·hm
−2 for ryegrass and 180 kg·hm
−2 for oat grass. The optimized irrigation rate was 5 737 m
3·hm
−2 for alfalfa. [Conclusion] There was still a huge potential to increase yield of alfalfa, ryegrass and oat grass. The yield gaps of alfalfa, ryegrass and oat grass were 17, 10 and 13 t·hm
−2. Furthermore, reasonable fertilizer application rate, sowing rate and irrigation rate are important to cut yield gap. By optimizing the fertilizer application rate, the yield of alfalfa, ryegrass and oat grass could increase by 3.4, 1.5 and 4.2 t·hm
−2. Suitable sowing rate could increase the yield by 60% for alfalfa, 78% for oat grass, but it was not enough to improve the yield of ryegrass only by adjusting the sowing rate. Optimal irrigation rate could increase the alfalfa yield by 9.1 t·hm
−2.
[Objective] Phosphorus (P) is one of the essential mineral elements for animals. It plays an important role in the growth, development and production of livestock. However, the use efficiency of P in animal production is very low, a large amount of undigested feed P is excreted with manure, and the P enrichment in the environment results in serious P pollution, such as eutrophication. Feed P level and phosphate supplementation are closely related to the P use efficiency and manure P excretion. The objective of this study is to determine the status of P level and phosphate application of animal feed in China, and to provide a scientific basis for rational use of feed P resource and reduce the excretion of manure P. [Method] The variance of the P requirement recommended by American feeding standard and Chinese feeding standard and the actual P content and phosphate supplementation in the feed were studied in this research by conducting literature analysis, surveys, and experiments. [Result] For swine, compared with the Chinese standard, the current American standard recommends the P requirements as total P, standardized total tract digestible (STTD) P, and apparent total tract digestible (ATTD) P, with no recommendation for non-phytate P (NPP). For laying hens, broilers, meat ducks, the American standard lists NPP requirements, but not total P requirement. For dairy cattle, the total P requirement recommended by the Chinese standard is 31%, 74%, and 26% higher than the American standards for heifers, milking cows, and dry cows, respectively. Compared with the American standards, the current Chinese feeding standard is higher in the NPP requirement for laying hens (0.32%
vs. 0.25%), slaughter chickens (0.35%–0.40%
vs. 0.30%–0.35%), and meat ducks (0.35%–0.42%
vs. 0.30%–0.40%). The majority of phosphates used in feed in China is dicalcium phosphate (DCP), then the mono-dicalcium phosphate (MDCP) and monocalcium phosphate (MCP). The contents of phosphate, total P and NPP of same feed produced by different enterprises varied greatly. The use of calcium phosphate in commercial feeds in China was 8.8 kg·t
−1 in 2016 on average, decreasing from 12.0 kg·t
−1 in 2006. The total P requirement of animals and poultry used by the feed industry in 2016 was similar to that used in 2006 based on surveys, consistent with the Chinese standards. However, the NPP requirement used by the feed industry was higher than those recommended by both the Chinese standards and the American standards for laying hens, growing pigs, and finished pigs. [Conclusion] The P requirements of dairy cows, laying hen, later stage of broiler, and meat duck recommended by Chinese feeding standard were higher than the American standard; the use of calcium phosphate in commodity feeds in China was 3.2 kg·t
−1 in 2016 lower than in 2006 on average; the NPP requirement used by the feed industry was higher than the recommended by both the Chinese feeding standards and the American feeding standards for laying hens, growing pigs, and finished pigs. It is suggested that the study of phosphorus requirement should be carried out based on the animal varieties and feed characteristics in China to modify the recommended standards for phosphorus requirement of animals. At the same time, we need to adopt the measures of using the low-phosphorus diets, the high utilization rate of calcium phosphate and addition of phytase in feed to improve the efficiency of feed phosphorus utilization, and to reduce the P excreted with manure.
Crop-livestock system includes two sub-systems of animal production and soil-crop production. Manure management is the most important part to connect animal production and soil-crop production. Ammonia emission occurs in the chain of livestock housing, manure storage, manure processing and application. Crop-livestock system is the great contributor to ammonia emission in the world, and currently higher ammonia emission has made the local air quality worse. Ammonia emission mitigation options in crop production and the whole feeding-livestock housing-storage-processing-application chain of livestock production have been a hot topic for many years. In this study, we consider the whole manure management chain and fertilizer application when the ammonia mitigation techniques are summarized. In the past decades, plenty of ammonia emission mitigation studies have been conducted in America and European countries. Studies on ammonia mitigation technique mainly focused on fertilizer application in China, and the studies on livestock production chain in China just started in recent years. Here, ammonia emission mitigation techniques from the world were comprehensively reviewed in this study. The mitigation mechanisms, effects and feasibilities of the technique were discussed. We also presented further directions and significances of ammonia mitigation research. The suggestions are as follows: (1) The present study on ammonia emission mitigation mainly focus on specific part and single technique of crop-livestock system. However, the integrated mitigation options of the whole chain are lack especially in China. We suggest consider economic factors, gaseous emissions and animal welfare to create a comprehensive ammonia mitigation technique package. (2) China should vigorously support the study of ammonia emission mitigation techniques and related equipment. The studies should include the principles, regulations, costs and benefits analysis of ammonia emission mitigation techniques. Meanwhile it is also important to promote the extensions of ammonia mitigation techniques. (3) It is suggested that the subsidy policy of ammonia mitigation technique should be formulated to promote the mitigation of ammonia emission in crop and animal production.
[Objective] The paper makes a scientific judgement on the trend and impact of agricultural non-point source pollution (NPSP), which is important for policy strategy in the future. To better solve the current problems and correct policy deviations in a timely manner, evaluation on policy implementation is necessary. [Method] A comprehensive review of the relevant policies of China in the field of agricultural NPSP control since the 1970 s was made. The current policies of agricultural NPSP were evaluated with methods of documentary analysis, field survey, and literature review. [Result] As the statistic and monitoring system being more complete, the data of emission quantity for agricultural NPSP will get larger, and its impact on water quality will be more directly. At present, agricultural NPSP is concerned by the society and the government. At the same time, the demand for agricultural transformation is urgent. The top-level design of the policy has been basically formed, but it is important to guard against formalism in the implementation of the policy. The realization of the goal of zero growth of chemical fertilizer is more certainly, while the zero growth target of pesticides faces more uncertainty, and all of them need to guard against falling into the ‘numeric game’ trap. The pollution control of livestock and poultry is restricted and lacks motivation, which seriously hinders the comprehensive utilization of livestock and poultry manure. The ‘forbidden-burning’ policy on straw regardless of cost, spends a lot of manpower and material resources, which need to be reconsidered. [Conclusion] In the long run, the prevention and control of agricultural NPSP need to make long-term preparation, improve the monitoring system, find out the actual situation, and avoid ‘numeric game’. The implementation of policies must be stressed. Supply side structural reform is necessary for agricultural inputs in order to reduce the quantity of chemical use. At the end of agricultural producing, reuse is the major outlet of the by-products such as straw and manure. The public financial investment for agricultural NPSP control should be increased, and matched with its emission ratio.
