Nutrient management and balanced fertilization in Inner Mongolia

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-P₂O₅-K₂O/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-P₂O₅-K₂O/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-P₂O₅-K₂O/ha. Agronomic efficiencies were 2.7 kg seed/kg N, 5.5 kg seed/kg P₂O₅, and 2.0 kg seed/kg K₂O, 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-P₂O₅-K₂O/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-P₂O₅-K₂O/ha produced 39, 36, and 54% more grain yields than the N, P, and K omission plots. Application rates of N, P₂O₅ and K₂O 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