Americas and Oceania Group - International Plant Nutrition Institute

Effect of Long-term Application of Potash and Straw Return on Wheat Yield and Soil Potassium Balance in Qinghai Province
Project Leader: Zhanquan Chen, Soil and Fertilizer Institute, Qinghai Academy of Agriculture and Forestry, Xining,
Qinghai. E-mail: zqchen@ipni.ac.cn
This fixed-site, irrigated spring wheat experiment is on a loamy, Chestnut soil site in northeastern Xining
City of Qinghai Province since 1993. The study is evaluating the long-term agronomic effects of NP and NPK
treatments used in combination with complete, 50%, and zero straw recycling.
In 2011, after 19 years of study, wheat yield of NP treatment was 5.9% lower than that of NPK treatment.
Use of NP plus 50% or 100% straw recycling were as productive as the NPK treatment. Straw recycling with
fertilizer K generated similar yield to straw recycling without fertilizer K. The K balance in the NP treatment
was -139 kg/ha, while in the NPK treatment, it was -21 kg/ha. Partial and complete straw recycling without
fertilizer K application generated a soil K deficit of -84 kg/ha and -14 kg/ha, respectively. Only the NPK plus
straw return could maintain a positive soil K balance and soil K surplus. Testing of soil physical properties
indicated that straw returning decreased soil bulk density and increased soil moisture content. Qinghai-2011
Nutrient Management and Balanced Fertilization for Major Crops in Shaanxi
Project Leader: Yan’an Tong, College of Resources and Environment, Northwest A & F University Soil and Fertilizer
Institute, Yangling, Shaanxi. E-mail: Tongyanan@nwsuaf.edu.cn
Project Cooperators: Yimin Gao, Shulan Zhang, and Ruliang Liu
Experiments in 2011 focused on water and nutrient interaction in apple and NPK application ratio in kiwi in
Shaanxi Province. The nutrient and water interaction research was conducted in a 9-year-old Fuji apple orchard
(1,667 trees/ha) at Fengxiang County and a 5-year-old Fuji apple orchard (1,667 trees/ha) at Pucheng County.
At the nutrient recommendation of 0.6-0.24-0.3 kg N-P 2 O 5 -K 2 O/tree, drip fertigation at four growing stages
(viz., 20% at basal, 30% at bud emergence in the spring, 50% at fruit expending [30% on Jun 10, 20% on July
20]) produced 14% and 8% more fruit yield in Fengxiang and Pucheng counties, respectively than the same
amount of nutrients applied in soil at four stages, but with flood irrigation. Half of the recommended nutrients
plus the drip fertigation produced similar or more fruit yield to the fully recommended nutrients applied
with flood irrigation. Economic analysis indicated that fertigation resulted in USD 7,089/ha more income in
Fengxiang County and USD 2,160/ha more income in Pucheng county than flood irrigation practice.
Research on NPK ratio in Kiwi in Yangling City determined 0.23-0.12-0.12 kg N-P 2 O 5 -K 2 O/tree (2,000
trees/ha) to be the optimal fertilization dose. This dose produced 47.7 t/ha of kiwi fruit—12, 12, and 26%
more than the 1/2N, 1/2P, and 1/2K treatments, respectively. These yield gaps produced more value for
the optimal dose by USD 3,861, 4,019, and 7,604/ha, respectively. Evaluation of an additional treatment
supplying 50% more NPK resulted in similar yield to NPK. The NPK recommendation plus 8 kg farmyard
manure generated 3% more yield over NPK alone, and increase profits by USD 1,007/ha. Shaanxi-NMBF
Nutrient Management of Cotton and Processing Tomato with Drip Irrigation in Xinjiang Province
Project Leader: Yan Zhang, Soil and Fertilizer Institute, Xinjiang Academy of Agricultural Sciences, Urumchi,
Xinjiang. E-mail: yzhang@ppi.caas.ac.cn; zhangy@xaas.ac.cn
Project Cooperators: Wei Hu, Yinkun Yao, Yuan Gao, Mingyao Tang, Fengxuan Meng, Hua Liu, Yongchun Qi, Xiong
Zeng, Denjiang Liu, Shifa Qi, Guihong Qi, and Haiyan Wang
Agriculture in Xinjiang is water dependent, and more than 90% of crops here are irrigated. Drip irrigation
continues to be most popular in crops such as cotton and processing tomato. The study in 2011 mainly
focused on balanced fertilization and P management in cotton and processing tomato.
In the drip-irrigated cotton grown in Changji City, the recommended NPK rate of 240-150-75 kg N-P 2 O 5 -
K 2 O/ha and its corresponding omission plots found N to be most limiting followed by P and then K.
Agronomic efficiencies (AE) at the recommendation fertilizer rate were 7 kg seed cotton increase/kg N, 7 kg
seed cotton increase/kg P 2 O 5 , and 54 kg seed cotton increase/kg K 2 O, while recovery efficiencies (RE) were
56, 25, and 58%, respectively. Basal application of 65% of the recommended P rate before planting and the
remaining 35% applied through drip irrigation produced 6% more yield than 100% basal application, and also
improved P use efficiency. Fertigation with reduced P rate (2/3 recommended P) produced 5% more yield
than 100% recommended P as basal application.
In drip-irrigated processing tomatoes grown in Changji City, the recommended NPK rate of 360-210-120
kg N-P 2 O5-K 2 O/ha increased tomato yields by 567, 16, and 5% when compared with yields in -N, -P and
-K plots, respectively. Agronomic efficiencies at the recommended fertilizer rate 77 kg tomato/kg N, 49 kg
tomato/kg P 2 O 5 , and 32 kg tomato/kg K 2 O, while RE were 48, 25, and 54%, respectively. Application of P
with fertigation produced similar tomato yields as with 100% basal application. Shaanxi-NMBF v
80 IPNI Interpretive Summaries