what can we learn from long-term paddy and vegetable field experiments for better nutrients management and less environmental impact in Taihu Lake region? Institute of Soil Science Chinese Academy of Sciences Nanjing, China Ju MIN, Jun QIAO, Tingmei YAN, Xu ZHAO, Weiming SHI 中中中中中中中中中中中中中中中中中 China-UK nutrient management and water resource protection workshop
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Institute of Soil Science Chinese Academy of Sciences Nanjing, China
中英养分管理和水资源保护学术研讨会 China-UK nutrient management and water resource protection workshop. what can we learn from long-term paddy and vegetable field experiments for better nutrients management and less environmental impact in Taihu Lake region?. Ju MIN, Jun QIAO, Tingmei YAN, Xu ZHAO, Weiming SHI. - PowerPoint PPT Presentation
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what can we learn from long-term paddy and vegetable field experiments for better nutrients management and
less environmental impact in Taihu Lake region?
Institute of Soil Science Chinese Academy of Sciences
Nanjing, China
Ju MIN, Jun QIAO, Tingmei YAN, Xu ZHAO, Weiming SHI
中英养分管理和水资源保护学术研讨会China-UK nutrient management and water resource protection workshop
N Runoff
Leaching
To obtain high yield, large amount of fertilizer N is applied in China.
Consequently, considerable amount of N enters the environment through volatilization, runoff and leaching. This threat to environment is more serious in the Taihu Lake region.
volatilization
A typical rice-wheat rotaion field in Yixing, Jiangsu Province, the experiment starts 2008 (6y, 12 crop season) (another from 2003)
Experimental site:
Taihu Lake
TO evaluate fertilizer N impact on environment and balance of high yield and environmental cost, two
long-term field experiments were conducted
A typical greenhouse vegetable production farm in Yixing, Jiangsu Province, the experiment starts from 2005 (8y, 24 crop seasons)
Cropping system: Double crops: rice-wheat (from 2008 to 2013) rice-alfalfa (from 2010 to 2013)
By decreasing traditional rate of synthetic N fertilizer by 30% run off was reduced by 33% without any yield loss in rice season under rice-wheat rotation
Alfalfa-Rice rotation
Rice yield (kg/ha)
2010 2011 2012 2013 Average
CK 4789±179 6275±234 5414±90 5594±371 5518
11%N 5034±90 6306±89 5766±261 6262±115 5842
22%N 5478±334 6901±374 6572±1074 6670±129 6407
33%N 5794±357 7088±482 6887±641 7201±167 6742
44%N 5942±80 7412±200 7411±641 7399±160 7041
55%N 5879±174 7296±184 7725±199 7264±656 7041
100%N 6735±208 7084±665 8778±558 7317±477 7479
Control measures : Optimizing N input and Alfalfa-Rice rotation
When alfalfa incorporated into rice cropping system, decreasing traditional rate of synthetic N fertilizer by 56% ( 44%N ) will not lead any yield loss in rice season.
Alfalfa-Rice rotation
Annual runoff (kg N/ha)
2010 2011 2012 Average
CK 5.96±1.14 1.83±0.37 6.02±0.88 4.60
11%N 6.99±1.44 1.90±0.18 6.18±1.02 5.02
22%N 9.54±1.22 2.27±0.12 6.50±0.81 6.10
33%N 11.26±0.63 3.67±1.20 6.75±0.97 7.23
44%N 16.02±1.43 6.08±1.35 7.12±1.15 9.74
55%N 18.50±2.26 6.99±2.06 7.96±0.92 11.15
100%N 29.88±3.28 20.78±4.26 31.41±6.52 27.36
Compared to local farmers’ normal N usage, reducing fertilizer N input by 56% under Alfalfa-Rice rotation reduced total N runoff by 64%.
The annual runoff in different N rates under Alfalfa-Rice rotation
N fate under the greenhouse vegetable cropping system in
Taihu Lake region.
(Min, et al. Pedosphere, 2011; Min, et al. Soil Use and Management, 2012)
Control measures: Optimizing N input
The optical N input is 930 kg N/ha (manure + synthetic N: 234+696)
( kg/ha)
By decreasing traditional rate of synthetic N fertilizer by 40% leaching loss was reduced by 39% without any yield loss in intensive greenhouse vegetable production systems. (Min, et al. Agricultural Water Management, 2011)
Optimizing nitrogen input to reduce nitrate leaching loss in greenhouse vegetable production
RNL: Reduced N leaching
Treatment 2007 2008 2009 2010 2011 2012 6 Y average
R N L Yield R N L Yield R N L Yield R N L Yield R N L Yield R N L Yield R N L Yield
The effect of catch crop on the amount of total N leached (kg/ ha) and the relative total N captured by the catch crop in 2008 and 2009
(Min, et al. Nutr Cycl Agroecosyst, 2011)
Compared to local farmers’ normal N usage, reducing fertilizer N input by 20 and 40% with a sweet corn catch crop reduced total N leaching by 50 and 73%, respectively.
Control measures: Catch crop
Conclusions1. In rice cropping system:
Optimal N input is 190 kg N/ha in rice season under rice-wheat rotation.
3% and 12% N were lost by runoff and leaching under farmer’s N input level .
By decreasing traditional rate of synthetic N fertilizer by 30% run off was reduced by 33% without any yield loss in rice season under rice-wheat rotation.
By decreasing traditional rate of synthetic N fertilizer by 56%( 44%N ) under Alfalfa-Rice rotation reduced total N runoff by 64% and also maintain the rice yields.
Optimal N input is 930 kg N/ha for vegetables.
3% and 20% N were lost by runoff and leaching under farmer’s N input level .
By decreasing traditional rate of synthetic N fertilizer by 40%, leaching loss was reduced by 39% without any yield loss;
Compared to local farmers’ normal N usage, reducing fertilizer N input by 20 and 40% with a sweet corn catch crop, this reduction could reach to 50 and 73%, respectively.
2. In greenhouse vegetable cropping system:
研究进展
Long-term rice-vegetable rotation experiments was started in 2013 in this region. Cropping system: Rice-vegetable rotation: Cabbage-rice-brassica chinensis CK: Cabbage-kidney bean-radish-brassica chinensis
Fertilizer treatments : 1) 100%N (traditional synthetic N rate) 2) 70% N 3) 40%N 4) CK (no synthetic N)