Nutrient management and balanced fertilization in Inner Mongolia

IPNI-2006-CHN-NM1

23 Jan 2009

2008 Annual Interpretive Summary

Nutrient Management and Balanced Fertilization in Inner Mongolia, 2008

Field experiments were conducted on potato, sunflower, and rapeseed to document yield responses to applied nutrients, and clarify the principles of biomass and nutrient accumulation and nutrient use efficiency in these prominent crops of Inner Mongolia.

In rainfed potato in Wuchuan County, application of 105-60-90 kg N-P2O5-K2O/ha proved most effective with significant yield improvements over nutrient omission treatments. The best treatment for irrigated potato at this site was 150-75-105 kg/ha, placing more emphasis on P and K. Potato experiments in Zhongqi County using 180-90-120 kg/ha as the balanced fertilization (OPT) treatment in both sprinkler irrigated and flood irrigated systems found larger, positive yield gaps between the OPT and all nutrient omission plots with sprinkler irrigation than flood irrigation. The amount of N and K required for each tonne of tuber yield was higher under sprinkler irrigation compared to flood. Sprinkler irrigation not only increased tuber yield, but also increased nutrient use efficiency compared with flood irrigation.

Experiments on sunflower for oil in Hangjinhouqi, Linhe, and Wuyuan Counties demonstrated highest average seed yields under the selected OPT of 165-60-180 kg/ha. Agronomic efficiency (kg seed increase per kg added nutrient) for the OPT was 3.9 kg seed/kg N, 6.7 kg seed/kg P2O5, and 2.6 kg seed/kg K2O, and recovery efficiency for N, P, and K fertilizer was 36%, 15%, and 30%, respectively. About 5.3 kg N, 0.8 kg P2O5, and 5.9 kg K2O was required to produce 100 kg sunflower seed.

In oilseed rape, the OPT of 135-45-60 kg/ha was most effective. Agronomic efficiency for the OPT was 2.1 kg seed/kg N, 7.9 kg seed/kg P2O5, and 3.0 kg seed/kg K2O, while recovery efficiency of N, P, and K fertilizer was 20%, 16%, and 20%, respectively. About 6.0 kg N, 2.0 kg P2O5, and 2.2 kg K2O was required to produce 100 kg seed.

Accumulation of biomass and nutrient uptake by irrigated and rainfed potato, rapeseed, and sunflower were also evaluated for future consideration regarding nutrient management in these crops. Inner Mongolia-NMBF