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Copyright of Journal of Ballistics / Dandao Xuebao is the property of Journal of Ballistics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In recent decades, China's livestock and poultry industry developed rapidly, producing plentiful of livestock and poultry manure and urine. But their quantity, nutrient content, rate of returning to cropland in different regions, and the changes of quantity over time have not been fully understood. In this paper, based on official statistical data and literature reviews, we estimated the quantity of animal feces, nutrient resources and their rate of returning to cropland at provincial level in various time slots. Results showed that, in 1980s, 1990s, 2000s and 2010s, the amount of animal feces (fresh) in China was 27.62×108, 39.11×108, 44.59×108 and 42.34×108 metric tons, respectively, increased by 53.32% in 30 years. The total nutrient N, P and K resources of animal feces in 1980s, 1990s, 2000s and 2010s were 2 523.86×104 t (N 1 249.47×104 t, P2O5 230.64×104 t, K2O 1 043.75×104 t), 3 686.59×104 t (N 1 820.79×104 t, P2O5 327.13×104 t, K2O 1 538.67×104 t), 4 296.77×104 t (N 2 124.13×104 t, P2O5 401.29×104 t, K2O 1 771.35×104 t) and 4 089.40×104 t (N 2 017.66×104 t, P2O5 421.17×104 t, K2O 1 650.57×104 t), increased by 62.03% in 30 years and Northeast China had the greatest increase. About 40% of China total amount of animal feces and the corresponding nutrients was derived from Henan, Sichuan, Shandong, Hunan, Yunnan and Inner Mongolia. The ratio of specific animal feces and nutrients in China was in the sequence of cow > pig > sheep > poultry > horse > donkey > mule, but varied in different regions. Northwest China, Southwest China and Northeast China had the higher proportions of cow feces and the corresponding nutrients, the Middle Lower Reaches of the Yangtze River had the highest proportion of pig feces and the corresponding nutrients, the Northwest China had the highest proportion of sheep feces and the corresponding nutrients, the Southeast China had the highest proportion of poultry feces and the corresponding nutrients. The ratios of feces and the corresponding nutrient quantity from horse, donkey and mule were relatively small in various regions. In 1980s, 1990s, 2000s, 2010s the total amount of nutrient N, P and K returning to cropland reached 1 132.73×104, 821.36×104, 1 860.52×104 and 1 709.19×104 t, respectively, accounting for 44.88%, 22.28%, 43.30% and 41.80% of total resources, respectively. About 50% of the total nitrogen, phosphorus and potassium nutrient returning to cropland from animal feces was occurred in Hebei, Henan, Shandong, Hunan, Inner Mongolia, Sichuan, Yunnan and Guangxi. By 2010s, N, P2O5, K2O from animal feces returned to cropland was 615.91×104, 297.70×104 and 795.58×104 t, accounting for 30.53%, 70.68% and 48.20% of the total quantity, respectively. This investigation can provide scientific basis and reference for the rational utilization of nutrient resources from animal feces and nutrient management under zero growth of chemical fertilizer in different provinces or regions in China. [ABSTRACT FROM AUTHOR]

Crop straw resource in China is plentiful, but in different regions the straw resource capacity, the corresponding nutrient resource capacity and available amount of returning to farmland as well as the changes over time have not been very clear. Based on official statistical data and literature review, this study analyzed the capacity of crop straw, the corresponding nutrient nitrogen (N), phosphorus (P) and potassium (K) and available amount of returning to farmland in different time slots at provincial level, aiming to provide scientific basis and reference for rational utilization of straw nutrient resources and nutrient management under zero growth of chemical fertilizer. Results indicated that the capacity of crop straw and its NPK nutrients increased by 85.77% and 104% from 1980s to 2010s, respectively. Among the regions, the increase of crop straw capacity and NPK nutrients in Northwest, Tibet Autonomous Region and Heilongjiang Province was more obvious. The crop straw and its nutrient capacity in North Plain, middle and lower reaches of Yangtze River, Sichuan Basin and Heilongjiang Province accounted for two-thirds of the total capacity in China. By the 2010s, the total crop straw and its total N, P and K capacity in China have reached 9.01×108 and 2 485.63×104 t, respectively, equivalent to per unit area of farmland of 6 665.56 and 183.91 kg/hm2, 1 601.18 and 56.85 kg/hm2 more than those in 1980s, respectively. Great variability existed among different regions in the capacity of straw and its nutrients from specific kinds of crops. In 2010s, the proportions of crop straw and its nutrient capacity from cereal crops accounted for 69.86% and 56.47% of the total capacity in China, respectively, and the highest proportions of cereal crop straw and its nutrient capacity occurred in Northeast region. The capacity of crop straw and nutrient from fruits and vegetables accounted for 9.67% and 21.99% of the total capacity in China, respectively, and the Northeast region had the highest proportions of straw and nutrient capacity of fruit and vegetable. The proportions of straw and nutrients capacity from beans, potatoes, oil crops, cotton and other fiber crops were relatively small. The amount of direct straw returning to farmland has continually increased from 1980s to 2010s, while the amount of straw returning to farmland after burning increased from the 1980s to 2000s, and decreased in 2010s. However, the total amount of straw NPK nutrients returning to farmland has increased continually from 1980s to 2010s. The total NPK nutrients increased from 583.92×104 t (N 97.81×104 t, P2O5 40.10×104 t and K2O 446.01×104 t) in 1980s to 1 770.66×104 t (N 574.53×104 t, P2O5 105.53×104 t and K2O 1 090.60×104 t) in 2010s, equivalent to per unit area of farmland of 60.89 kg/hm2 (N 10.20 kg/hm2, P2O5 4.18 kg/hm2, K2O 46.51 kg/hm2) in 1980s to 131.0 kg/hm2 (N 42.5 kg/hm2, P2O5 7.8 kg/hm2, K2O 80.7 kg/hm2) in 2010s. The ratio of crop straw NPK nutrients returning to farmland was 47.92%, 56.16%, 60.11% and 71.24%, respectively in 1980s, 1990s, 2000s and 2010s. From 1980s to 2000s, the increase of the ratio of crop straw NPK nutrients returning to farmland in Inner Mongolia, Xinjiang and Heilongjiang was obvious, but the total amount of crop straw NPK returning to farmland in the North Plain, the middle and lower reaches of the Yangtze River and Sichuan Basin accounted for more than two-thirds of total crop straw NPK returning to farmland in China. [ABSTRACT FROM AUTHOR]