Americas and Oceania Group - International Plant Nutrition Institute

Asia and Africa Group
China
Northwest Region: Dr. Shutian Li
Nutrient Management and Balanced Fertilization in Ningxia
Project Leader: Youhong Li, Soil and Fertilizer Institute (SFI), Ningxia Academy of Agricultural Sciences, Yinchuan,
Ningxia. E-mail: youhongli@vip.sina.com, fangwang@vip.sina.com
Project Cooperators: Fang Wang and Tiancheng Zhao
Two experiments were conducted in 2011 in Ningxia province to: (a) investigate limiting nutrients for
maximum rice yields by comparing the yields in optimal treatment (OPT) with yields obtained in nutrient
omission plots; and (b) determine the optimal K rate for cabbage.
An OPT trial in rice was conducted in Lingwu city. Results showed that the average yield with
recommended OPT (225-90-75 kg N-P 2 O 5 -K 2 O/ha) was 10,292 kg/ha, which was 141%, 4%, and 2% more
than that obtained plots omitting N, P, and K, respectively. This indicated N as the main limiting factor in rice
production in Ningxia, while P and K were found to be sufficient.
A potash rate trial in cabbage in Lingwu showed that increasing K rates increased cabbage yield by 13.1%
to 20.8%. The highest cabbage yield was obtained with 300-150-225 kg N-P 2 O 5 -K 2 O/ha treatment. Increasing
K rates to 300 kg K 2 O/ha reduced cabbage yield by 6.7%. However, there was no statistically significant yield
difference between 225 and 150 kg K 2 O/ha treatments. Economic analysis showed that the highest income
(USD 300/ha) was obtained in 150 kg K 2 O/ha treatment, which incidentally also had higher K recovery
efficiency of all K treatments. In summary, the appropriate rate of K in cabbage in Lingwu, Ningxia, was
found to be 150 kg K 2 O/ha. Ningxia-NMBF
Nutrient Management and Balanced Fertilization in Inner Mongolia
Project Leader: Debao Tuo, Institute of Plant Nutrition and Analysis (IPNA), Inner-Mongolia Academy of Agricultural
Sciences (IMAAS), Huhhot, Inner Mongolia. E-mail: tuodb@263.net
Project Cooperators: Yu Duan, Peiyi Zhao, and Huanchun Li
Field trials were conducted on irrigated/rainfed potato, sunflower, and maize to demonstrate: (1) yield
responses to balanced fertilization, and (2) effect of nutrient management under rain collecting or irrigation
on crop yield and nutrient use efficiency.
In flood irrigated potato in Wuchuan County, application of 240-90-165 kg N-P 2 O 5 -K 2 O/ha produced 44.3 t/
ha, which was 16%, 14%, and 12% more than the yields in N, P, and K omission plots, respectively. A rainfed
potato trial produced 18.9 t/ha with 150-60-75 kg N-P 2 O 5 -K 2 O/ha, which was 22%, 30%, and 20% more than
the yields in N, P, and K omission plots. Nitrogen and K recovery efficiencies under irrigation were 50%
and 65%, while in rainfed conditions, these were lower at 22% and 39%, respectively. A study on rainfed
potato at the Wuchuan Experimental Station found that plastic mulch coverage for collecting rainfall could
produce 25% more tuber yield, and 9.9, 5.0, and 22% higher N, P, and K recovery efficiencies, respectively,
as compared to no plastic mulch coverage.
Sunflower experiments in Wuyuan County demonstrated highest seed yields under the optimum (OPT)
treatment of 225-75-135 kg N-P 2 O 5 -K 2 O/ha. Agronomic efficiencies were 2.7 kg seed/kg N, 5.5 kg seed/kg
P 2 O 5 , and 2.0 kg seed/kg K 2 O, and the average recovery efficiencies for N, P, and K fertilizer were 26.7, 17,
and 54%, respectively. Compared with farmer practice (225-225-0 N-P 2 O 5 -K 2 O/ha), OPT produced 12.7%
more seed yield and USD 494 more profit.
Results from a sprinkler-irrigated maize trial at Dalate County, Erdos, revealed that application of 270-
120-180 kg N-P 2 O 5 -K 2 O/ha produced 39, 36, and 54% more grain yields than the N, P, and K omission
plots. Application rates of N, P 2 O 5 and K 2 O for optimum economic yield were 238, 114, and 128 kg/ha,
respectively. Accumulation of biomass and nutrient uptake in plastic mulch covered potato, sunflower, and
sprinkler irrigated maize were also evaluated for future consideration regarding nutrient management in these
crops. Inner Mongolia-NMBF
IPNI Interpretive Summaries 79