Nutrient management and balanced fertilization in Inner Mongolia

Balanced fertilization trials were conducted in irrigated potato, oil sunflower and irrigated maize in Inner Mongolia to demonstrate yield response, nutrient use efficiency and economic benefit with balanced fertilization.

For irrigated potato in Wuchuan County, application of 240-90-165 kg N-P₂O₅-K₂O/ha produced the highest yield of 33 t/ha, which was 27, 6 and 8% more than the yields obtained in N, P and K omission plots. The agronomic efficiencies were 29 kg tuber/kg N, 21 kg tuber/kg P₂O₅ and 15 kg tuber/kg K₂O, while total recovery efficiencies were 24, 14 and 32%, respectively. The amount of nutrients required for each tonne of tuber yield were 5.5 kg N, 2.1 kg P₂O₅ and 7.8 kg K₂O. The average benefit with K application was US$263/ha.

For sunflower in Wuyuan County, application of N-P₂O₅-K₂O (KCl) at 225-75-135 kg/ha, respectively, produced a seed yield of 3.94 t/ha, which was 16, 10 and 9% more than the yields obtained in N, P and K omission plots. Among the K fertilizers used, KCl and K₂SO₄ produced similar yields at the same K rate. The agronomic efficiencies were 2.5 kg/kg N, 4.9 kg/kg P₂O₅ and 2.5 kg/kg K₂O. The amount of nutrients required for producing each tonne of seed were 45 kg N, 18 kg P₂O₅ and 86 kg K₂O. Another trial in Hanhou County indicated that the application of 150-60-120 kg N-P₂O₅-K₂O (KCl) produced a seed yield of 3.82 t/ha, which was 9, 11 and 6% more than the yields obtained in respective omission plots. The agronomic efficiencies were 2.1 kg/kg N, 6.2 kg/kg P₂O₅ and 1.8 kg/kg K₂O. The amount of N, P and K required for producing each tonne of seed were 42 kg N, 18 kg P₂O₅ and 103 kg K₂O. Oil sunflower required an average N: P₂O₅: K₂O ratio of 1:0.4:2.2. Potassium application resulted in $22/ha more profit, on average, than in the K omission treatment.

A trial with sprinkler irrigated maize conduced in Dalate County of Erdos indicated that the application of N-P₂O₅-K₂O at 270-120-180 kg/ha produced 13 t/ha maize grain, which was 21, 10 and 15% more than the yields obtained in N, P and K omission plots. The agronomic efficiencies of nutrients were 10.4 kg/kg N, 10.8 kg/kg P₂O₅ and 10.6 kg/kg K₂O. Potassium application resulted in $442/ha more profit, on average, than in the K omission treatment. Inner Mongolia-NMBF