Nitrogen and phosphorus use efficiencies in dairy production in China

Transcription

1 1 Supplementary Information Nitrogen and phosphorus use efficiencies in dairy production in China Z.H. Bai, L. Ma, O. Oenema, Q. Chen and F.S. Zhang* 6 7 Description Nutrient Flow Model in Dairy and Beef Production The nutrient flow model used in this study is a modified version of the NUFER model (Ma et al., 2010). The model uses a mass balance approach, and allows the calculation of nitrogen (N) and phosphorus (P) flows, use efficiencies in dairy and beef production systems in China, at the animal, herd and system levels for the whole China. Here, we present supplementary information about the feed composition, beef production systems, and about the partitioning of N and P flows, as used in the NUFER model Feed composition of dairy and related beef production in China are summarized in Table S1 and S2. 17 Main characteristics of the beef production systems are presented in Table S3. 18 The partitioning of N and P flows are showed in Tables S4, S5 and S Calculation methods Nutrient input by feed intake 1

2 22 Total dry matter intake was estimated from: 23 II DD iiiiii = II ffff ccccccccccc II ccc nnnnnn Feeding days [1] Where Ia DM intake (kg yr -1 ) is the amount of feed (dry matter) intake by dairy or beef; Ia feed composition (kg day -1 ) is the amount and composition of the feed per animal type; Ia cow number is the number of milk cow, beef cow, heifer or calves; Feeding days is feed intake time in a year, which was usually 365 days. Feed compositions were derived from Chen et al., 2012; Gao et al., 2011; Guo et al., 2006; Ma et al., 2010; Powell et al., 2008; Wang, 2005a. Cow number were derived from MOA, 2011, Wu et al., 2009, Wu et al., 2011, Wang, 2005b. 31 Total N and P intake was estimated from: 32 II nnnnnnnn iiiiii = II DD iiiiii II ffff ccccccccccccc 1000 [2] Where Ia nutrient intake (kg N yr -1 ) is the amount of nutrient (N or P) intake by calve, heifer, beef cow and milk cow; Ia DM intake (kg yr -1 ) is the amount of feed (dry matter) intake by dairy or beef; Ia feed concentration (g kg -1 ) is the nutrient concentrations of feed composition. Feed nutrient concentrations were derived from Ma et al., 2010, Wang, The composition of feed offered to calves, heifers and cows in dairy production systems is presented in Table S1. The composition of feed offered to beef cattle is presented in Table S2. Total feed consumption by all main animal species roughly matched the calculated total amount of feed available in China (Table S7). 2

3 43 44 Nutrient output in dairy and beef production The mass of N and P in animal products was estimated from: 45 OO mmmm = MM F mmmm [3] Oa milk (kg) is the nutrient output in milk (N or P); MY is the average yield of milk per cow, which derived from MOA, 2011 and Wang, 2005b. F milk is the nutrient content of milk OO mmmm = CCC nnnnnn LLL ccc + HHHHHH nnnnnn LLL heeeee + CCCCC nnnnnn LLL ccccc [4] Oa meat (kg) is the nutrient output in meat, Cow number, Heifer number and Calve number are the number of milk cows or beef cows, calves and heifers; LWG cow, LWG heifer and LWG calve are the average weight gain of milk cows or beef cows, calves and heifers in a year. These data were derived from Chen et al., 2009, Gao et al., 2011, Ma, 2009 and MOA, OO mmmmmm = II nnnnnnnn iiiiii OO mmmm OO mmmm [5] 58 Calculation of N losses from dairy or beef production system Manure N loss in housing and storage, grazing and manure application were calculated from the amount of manure N and NH 3, N 2 O, N 2, NO - 3 emission factors. Manure P loss via manure discharge, leaching, runoff and erosion was estimated from Ma et al., 2010 and Velthof et al.,

4 63 64 The mass of manure N and P dropped by grazing animals in the field were estimated from: 65 OO mmmmmm dddd = OO mmmmmm nuuuuuuu R ggggggg [6] Where Oa manure drop (kg) is the mass of manure dropped in the field; R grazing is the grazing time during 1 year. These parameters were derived from Ma et al., 2010 and Velthof et al., Gaseous N losses of manure during storage were estimated from: OO mmmmmm hoooooo llll = OO mmmmmm OO mmmmmm dddd (FFF3 + FF2O + FF2 + FFF3 ) [7] Where Oa manure loss in housing (kg) is the total N loss from manure in housing and storage sector; FNH3, FN2O, FN2 and FNO3- are the N emission factors for housing and storage. These parameters were derived from Ma et al., 2010 and Velthof et al., Manure discharges and manure applied to land were estimated from: OO mmmmm ddddhaaaa llll = OO mmmmmm OO mmmmmm dddd OO mmmmmm hooooog llll R ddddhaaaa [8] OO mmmmmm aaaaaaa = OO mmmmmm OO mmmmmm dddd OO mmmmmm hoooooo llll OO mmmmm ddddhaaaa llll R mmmmmm aaaaaaa [9] Where Oa manure to crop (kg) is the amount of manure used in crop production, R manure crop is defined as the rate of manure recycle used in crop. These parameters 4

5 83 were derived from Ma et al., 2010 and Velthof et al., OO mmmmmm llll = OO mmmmmm hoooooo llll + OO mmmmm ddddhaaaa llll [10] 85 Total fertilizer input into feed production was calculated from: II ffffffffff nnnnnnnn = II nnnnnnnn iiiiii NNN N oo P ffffff [11] Where the New N and P uptake factor are defined as: New N factor = Harvest N content / Applied fertilizer N, Harvest N content means the amount of nutrient content in crop product, while Applied fertilizer N is the average amount of fertilizer nutrient applied to certain kind of crop. These factor are collected from NUFER model ( Ma et al., 2010) Manure N and P emission factors for manure management in dairy production and beef production systems are presented in Table S Emission factors for NH 3, N 2 O, N 2, NO 3 - systems are presented in Table S5. emissions from crop production 97 The crop yield, BNF factors, new N and P uptake rates are shown in Table S6. 98 Total feed consumption by all animal species in China presents in Table S Detail results about N flows in beef production sub-systems are shown in Table S8 and Figure S References: 5

6 Chen J., Y.C. Wang, Y. Zhang, D.X. Sun, and Y. Zhang Estimation of economic values for production and functional traits in Chinese Holstein. J. Animal. Vet. Adv. 8: FAO, Gao, Z.L., H.J. Yuan, W.Q. Ma, X.J. Liu, and R.L. Desjardins Methane emissions from a dairy feedlot during the fall and winter seasons in Northern China. Environ. Pollut. 159: Guo Y.N., J.Q. Wang, L.F. Wang, L.Y. Zhou, and Y.Z. Jia The dairy cattle feeding status and countermeasures and suggestions for the main milk production region in China. (In Chinese.) J. Heilongjiang. Anim. Sci. Vet. Medic.5:1-4. Ma, L., W.Q. Ma, G.L. Velthof, F.H. Wang, W. Qin, F.S. Zhang, and O. Oenema Modeling nutrient flows in the food chain China. J. Environ. Qual. 39: Ma X.S Study on feed intake and digestibility of forage in different phenological periods for grazing holstein dairy cow--in Hulunbeier meadow steppe. (In Chinese.) College of Animal Science. Inner Mongolia Agric. Univ., Inner Mongolia. Ministry of Agriculture (MOA) China Husbandry yearbook. Minister of Agriculture. China Agric. Publ. House, Beijing. Powell, J. M., Y.X. Li, Z.H. Wu, G.A. Broderick, and B.J. Holmes Rapid assessment of feed and manure nutrient management on confinement dairy farms. Nutr Cycl Agroecosyst. 82:

7 Wang, F.H Nutrient flow analyses of China s animal agriculture.(in Chinese.) College of Resources and Environ. Sci., China Agric. Univ., Beijing. Wang L.F. 2005a. Study on production efficiency and milk quality in the main dairy areas (In Chinese). Chinese Academy of Agriculture Sciences. Beijing. Wang T.G. 2005b. Situation and outlook of feed utilization in dairy industry of China. (In Chinese). College of Animal and Technology. Sci., China Agric. Univ., Beijing. Wu L., J.B. Li, A.H. Li, and W. Wen The investigation of reproductive performance of dairy cows in Yinchuan, Ningxia. (In Chinese.) J. Agri. Sci. 30: Wu J.L., W.D. Zhou, J.F. Jiang, H.C. Zheng, X. Huang, X.M. Song, W. Cao, and Y.Q. Jiang Comparison of Chinese Holstein Cow Select Methods. (In Chinese.) Zhejiang. Agri. Sci. 2: Velthof, G.L., D. Oudendag, H.R. Witzke, W.A.H. Asman, Z. Klimont, and O. Oenema Integrated assessment of nitrogen losses from agriculture in EU-27 using MITERRA-EUROPE. J. Environ. Qual. 38:

8 Table S1. Mean feed composition of dairy production systems in China. Dairy system Traditional Collective feedlot Industrial feedlots Grassland-b ased Feed DM Input(kg head -1 yr -1 ) Animal By-product of Corn Soybean Vegetables food processing Straw Grass Leafs and green straw Milk Other Calve Heifer Cow Calve Heifer Cow Calve Heifer Cow Calve Heifer Cow N g.kg P g.kg Based on Guo et al., Based on Gao et al., Based on Chen et al., Based on Ma,

9 Table S2. Mean feed composition of beef production sub-systems in China. Beef system Draught beef Beef in pastoral Beef in feedlots Feed DM Input DM (kg head -1 yr -1 ) Animal By-product of Corn Soybean Vegetables food processing Straw Grass Leafs and green straw Residues Milk Other Calve Heifer Cow Calve Heifer 2929 Cow 2946 Calve Heifer Cow 9

10 Table S3. Parameters and coefficients related to beef production in three beef production sub-systems. Draught cattle Beef in pastoral Beef in feedlots Beef number (million cow) Calve live weight gain (kg yr -1 ) Heifer live weight gain (kg yr -1 ) Cow live weight gain (kg yr -1 ) Number of beef cows (Million heads) Number of heifers (Million heads) Number of calves (Million heads) Time of beef in the field in a year % MOA, 2011; Ma et al.,

11 Table S4. Manure nitrogen and phosphorus emission factors and manure management in dairy production and beef production systems. Dairy production system Beef production systems Traditional Grasslandbased pastoral feedlots Beef in Beef in Collective Industrial Draught NH 3 emission factor (%) N 2 O emission factor (%) Denitrification factor (%) Leaching factor (%) Manure N discharge rate (%) Manure applied rate (%) Manure export rate (%) Based on Ma et al., 2010; Velthof et al.,

12 Table S5. Nitrogen and phosphorus emission factor in different crop systems. Fertilizer N Manure N Grazing N All P NH 3 % N 2 O % Runoff % Erosion % Leaching % Denitrification % Accumulation % Based on Ma et al.,

13 Table S6. Mean yield, new N and P applied factor and BNF factor of main feed compositions. Yield kg ha -1 New N applied factor (%) New P applied factor (%) BNF kg N.ha -1 Corn Whole corn Natural Grass Managed Grass Soybean Data from FAO 2011 and Ma et al.,

14 Table S7. Total feed consumption by all animal species in China in 2005 (in Mt). Pig Hen Broiler Dairy Beef Draft Sheep Total Corn Soya Vegetables By-product of food processing Straw Grass Tubers Animal product Kitchen waste Leafs and green straw Residues P additives Milk Other Total

15 Table S8. Partitioning of the N and P losses from the beef production systems (in Gg). Draught cattle Beef in pastoral Beef in feedlot Total NH N 2 O N losses N NO Discharge Total Leaching P losses Runoff Erosion Discharge Total

16 N Feed import 1.8 By-product Feed Beef herd 361 Manure Meat Manure losses Deposition 5.4 Fertilizer 48 BNF 18 Grassland Cropland 23 Soil accumulation Manure export Field N losses P Feed import 0.1 By-product Feed Beef herd 56 Manure Meat Manure losses Grassland Manure export Fertilizer 13 Cropland Field P losses Soil accumulation Unit: Gg Figure S1. Nitrogen (upper figure) and phosphorus (lower figure) budgets in beef production in China in Numbers show the amounts of N and P in Gg. 16