Nutrient management and balanced fertilization in Inner Mongolia

Demonstrations using 30 t organic manure and 150-60-45 kg N-P₂O₅-K₂O/ha in four potato fields provided for yield increases between 5 to 17% and an average improvement in farm income of US$241/ha compared to the farmer practice (FP) which omitted K. Field experiments on irrigated potato in Wuchuan County indicated that balanced NPK use of 180-60-120 kg N-P₂O₅-K₂O/ha produced 6.8, 5.7, and 4.7 t/ha more than the - N, - P, and - K treatments, respectively. In rainfed potato, 125-45-60 kg/ha produced 1.2, 1.7, and 3.0 t/ha more than the - N, - P, and - K treatments. On average, 7.6 kg N, 1.2 kg P₂O₅, and 9.4 kg K₂O was required to produce 1 t of irrigated potato. In rainfed potato, 1 t of tubers required 8.0 kg N, 1.1 kg P₂O₅, and 6.6 kg K₂O.

A sunflower experiment in Bayanzhouer City found that balanced application of 180-60-60 kg/ha could produce 706 kg/ha (21%), 699 kg/ha (21%), 439 kg/ha (12%) more seed yield than the - N, - P, and - K treatments, respectively. About 3.1 kg N, 1.2 kg P₂O₅, and 2.9 kg K₂O were required to produce 100 kg sunflower seeds. Balanced use of NPK on sugar beet found the average yield under 180-60-60 kg/ha to be 16.1 t/ha (23%), 12.6 t/ha (17%), and 10.6 t/ha (14%) higher than the - N, - P, and - K treatments, respectively. About 3.6 kg N, 1.2 kg P₂O₅, and 6.8 kg K₂O were required to produce 1 t sugar beet.

In alfalfa, after application of 135-180-135 kg/ha, the total dry matter of three stand cuts from 2006 to 2007 was 1,045 t/ha (19%), 1,628 t/ha (34%), and 1,644 t/ha (34%) higher than the - N, - P, and - K treatments, respectively. Balanced fertilization on other forage grasses also significantly increased yield by 25 to 33%, 18 to 26%, and 16 to 19%, compared with - N, - P, and - K treatments, respectively. Inner Mongolia-NMBF