Americas and Oceania Group - International Plant Nutrition Institute

Research on Balanced Fertilization Technology of Sweet Potato
Project Leader: Prof. Zhang Yong Chun, Jiangsu Academy of Agricultural Science Resource and Environment Research
Center, Nanjing, Jiangsu. E-mail: Ychzhang66@sina.com
Project Cooperators: Wang Jidong, Ning Yunwang, and Zhang Hui
This project aimed to increase sweet potato yield and quality through optimum fertilization, and establish
the soil nutrient classification indexes and demonstrate balanced fertilization technology for sweet potato.
Field trials were carried out in Guanyun county and Liuhe district of Nanjing, Jiangsu province by Jiangsu
and Hubei Academy of Agricultural Science in 2011.
Results from Hubei and Jiangsu showed that the highest dry matter yield (13,905 kg/ha) and best net profit
were obtained with applications of 135 kg N/ha and 160 kg P 2 O 5 /ha. However, in Hubei, the highest dry
matter yield (9,600 kg/ha) and best net profit were obtained with applications of 165 kg N/ha and 248 kg
P 2 O 5 /ha. The results emphasized the need for developing site-specific fertilizer recommendations for a crop.
Jiangsu-11
Technologies for High Efficient Fertilization and Reduction of Non-point Source Pollution in Jiangxi
Project Leader: Guangrong Liu, Jianxi Academy of Agricultural Sciences Soil Fertilizer and Environmental Source
Institute, Nanchang, Jiangxi. E-mail: lgrtfs@sina.com
Project Cooperators: Fusheng Yuan, Zuzhang Li, Qixiang Luo, Gang Sun, Changxu Xu, Duogen Xiong, and Wenxue
Zhang
Apart from industrial pollution, non-point source pollution is another high priority concern in agricultural
production. Over application of fertilizers and pesticides not only degrades the environmental quality, but also
increases the cost of production. Therefore, a study on the non-point source pollution is important for making
policies, rules, and management systems. Field experiments with rice crop were carried out in 2011 by the
Soil and Fertilizer Institute, Jiangxi Academy of Agricultural Sciences to study fertilizer-saving, pollutionreducing,
and efficiency-improving agricultural production technology and its contribution to non-point
source pollution in Nanchang county. Treatments included: (1) NPK, (2) -25% NP, (3) -50% NP, (4) -25%
N + -50% P, (5) -50% N + -25% P, (6) OM (organic manure), (7) 50% OM + 50% CF (chemical fertilizer),
and (8) CK (no fertilization). In treatment 1, 150 kg N/ha, 75 kg P 2 O 5 /ha, and 150 kg K 2 O/ha were applied
to early rice and 180 kg N/ha, 60 kg P 2 O 5 /ha, and 180 kg K 2 O/ha to late rice. Nitrogen and K were applied as
50% basal, 30% was top dressed at tillering stage, and 20% top dressed at heading, while all P was applied
basal.
Results showed that applying NPK or 50% OM + 50% NPK gave similar early and late rice yields. This
implied that temporarily and properly reduced chemical fertilizer rates did not affect rice yields. To start with
the adoption of improved production technology, and based on farmers’common practice, we recommend
reducing N and P fertilizer rates by 25% to get same rice yield but with decreased risk of non-point source
pollution. Additional application of organic manure can significantly decrease the amounts of N and P loss in
run-off. Jiangxi-26
Efficient Nutrient Management For Forage Grasses and Animal Product Quality
Project Leader: Li Zu-zhang, Jiangxi Academy of Agricultural Sciences Soil Fertilizer and Environmental Source
Institute, Nanchang, Jiangxi. E-mail: lzztfs@126.com
Project Cooperators: Guangrong Liu, Gang Sun, Qingxiang Luo, Jinfang Xie, Fusheng Yuan, Wenxue Zhang, Huadong
Cai, Qing Ye, Zhihua Yi, and Xaingang Tang
In the world’s domestic animal industry, fodder and grain-saving domestic animals account for more than
90%, while the grain-consuming domestic animals only account for less than 10%. However in China’s
domestic animal industry, these two types of domestic animals account for 42% and 58%, respectively.
Therefore, developing the cultivation industry of herbivore domestic animals is an efficient practice for
keeping food security and sustainable agriculture. Herbivore domestic animals belong to grain-saving animal
category, so the cultivation cost and the negative effects on the environment are relatively low. There are over
1 M ha of winter fallow lands in Jiangxi that can be used for feeding the herbivore domestic animals. A field
experiment with Italian ryegrass under Mexico maize-Italian ryegrass cropping system was conducted in 2011
in Nanchang county of Jiangxi by the Soil and Fertilizer Institute, Jiangxi Academy of Agricultural Sciences,
to evaluate the effect of balanced nutrition management on yield of fodder crops and animal quality.
Results showed that Italian ryegrass significantly enhanced cow milk production by 84 to 88% compared
with other grasses. The yield of Italian ryegrass with application of (kg/ha): 500 N, 288 P 2 O 5 , 540 K 2 O,
74 IPNI Interpretive Summaries