Americas and Oceania Group - International Plant Nutrition Institute

Balanced Nutrient Management for Maximizing Rapeseed Yield in China
Project Leader: Lu Jian-wei, Huazhong Agricultural University Environment and Resources College, Wuhan, Hubei.
E-mail: lujianwei@mail.hzau.edu.cn
Project Cooperators: Jiang Cun-cang and Li Xiao-kun
In 2011, the IPNI China Program in collaboration with Huazhong Agricultural University conducted a total
of 40 rapeseed fertilization field trials in the main rapeseed production provinces such as Hubei, Hunan, and
Jiangsu with similar treatments in rice-rapeseed and cotton-rapeseed rotations. The treatments included: 1)
NPKB (N 180 kg/ha, P 2 O 5 70 kg/ha, K 2 O 100 kg/ha, Borax 7.5 kg/ha); 2) PKB; 3) NKB; 4) NPB; and 5) CK
(no fertilization).
Results from the trials showed that, in farms with rice-rapeseed rotation, the best average seed yield (2,508
kg/ha) was obtained with NPKB treatment. This treatment increased yields by 91, 25, 16, and 123% over
PKB, NKB, NPB and CK treatments, respectively. In farms with cotton-rapeseed rotation, the best average
seed yield (2,624 kg/ha) was again obtained with NPKB treatment, which increased yields by 56, 29, 23, and
86% over PKB, NKB, NPB and CK treatments respectively. Yield response to N fertilization in rice-rapeseed
rotation was better than that in cotton-rapeseed rotation, but the response of K fertilization was opposite, and
P fertilization showed a significant difference between the two systems. Hubei-35
Ecological Effect and the Utilization Rate of Potassium for Different Potassium Efficiency Cotton Genotypes
Project Leader: Jiang Cun-cang, Huazhong Agricultural University Resources and Environment College, Wuhan,
Hubei. E-mail: cotton2000@mail.hzau.edu.cn
Project Cooperator: Hao Yanshu
To identify genotypes with higher K efficiency and understand the mechanism of differences in response to
K deficiency among genotypes, a pot culture experiment was conducted in the greenhouse of the College of
Resources and Environment of Huazhong Agricultural University from May 7 to October 15, 2011. Study on
the effect of dry matter and K distribution and accumulation between 2 different cotton genotypes (high and
low K-use efficiency) was conducted with grafting technology.
Results showed that the effect of grafting on dry matter and K accumulation, distribution and yield was
different between the two cotton genotypes under different K conditions. After grafting, the ratio of dry
matter and K accumulation in the vegetative organ of high K-efficiency cotton genotype was increased, but
the same decreased in the reproductive organs. Moreover, yield and K utilization index also decreased. On the
contrary, the condition of low K-use efficiency cotton genotype gave an opposite effect. After grafting, the K
uptake efficiency of high K-use efficiency cotton genotype decreased with applied K and increased without
applied K. However, low K-use efficiency cotton genotypes reversed this trend, and their K uptake efficiency
increased with K application and decreased with no K application after grafting. In summary, we conclude
that the effect of grafting on different cotton genotypes was different. Hubei-37
Nutrient Transfer among Plant, Soil, and Environment in the Typical Cropping Systems of Hubei Province
Project Leader: Fan Xian-peng, Hubei Academy of Agricultural Science Soil & Fertilizer and Plant Protection Institute
Wuhan, Hubei. E-mail: Fan1965@163.com
Project Cooperators: Xiong Guiyun, Yang Li, Liu Dongbi, Zhang Fulin, Ba Ruixian, Yu Yanfeng, Zhang Jiming, Duan
Xiaoli, and Wu Maoqian
Nutrients are lost through runoff, leaching, and harvest, and at the same time increased through fertilization,
rainfall, irrigation, and straw return in the main cropping systems of Hubei province. These phenomenon were
studied by the Soil and Fertilizer Institute of Hubei in 2011.
Results from the 20 field experiments showed that nutrient loss in farmland through irrigation was mainly
of K, followed by N. Phosphorus loss through irrigation was very low. Soil nutrients from atmospheric
deposition mainly included N (11 to 47 kg/ha and 80% of this was NO 3-
), followed by K (6.5 to 76.6 kg/ha,
water-solubility K) and P (0.2 to 3.7 kg/ha, particulate P). The runoff water lost from the experimental sites
was 65 to 729 mm. The ratio of the amount of runoff water to the amount of rainfall was 0.22. The average
runoff amounts of total N, total P, and water-soluble K were 14.6, 1.5, and 24.6 kg/ha, respectively. These
values showed a positive correlation with the amount of runoff water, rather than with the rates of N, P, and K
application. Hubei-38
72 IPNI Interpretive Summaries