2005 - Soil Nutrient Management and Balanced Fertilization in Ningxia
2004 - Studies on Soil Nutrient Management Technology in Ningxia
2003 - Soil Nutrient Management and Fertilizer Use Strategies in Ningxia
2002 - Soil Nutrient Management and Fertilizer Use Strategies in Ningxia
Soil Nutrient Management and Fertilizer Use Strategies in Ningxia, 2003
Based on last year’s soil fertility evaluation at two monitored villages in Ningxia, work in 2003 focused on field research and demonstrations emphasizing rational phosphorus (P) and potassium (K) use for the major crops grown. In Lingwu County, two field trials, a K rate study, and 20 field demonstrations were arranged. At Huinong County, five field trials were conducted using wheat, Chinese cabbage, and onion.
Lingwu County: In the K rate study, 150 kg K2O/ha combined with 225 kg N/ha and 150 kg P2O5/ha produced the highest paddy yield of 12.0 t/ha, which was 0.9 t/ha (8.6%) higher than that of -K treatment, with a net benefit of US$93/ha.
Rice field trials showed the optimum (OPT) treatment of 225-225-150 kg nitrogen (N)-P2O5-K2O/ha produced the highest yield (13 t/ha). Omission of N, P, and K reduced yield by 39.2%, 11.5%, and 13.5%, respectively. The unfertilized control reduced yield by 51.4% (6.3 t/ha).
Results from 20 large field demonstrations covering 67 ha found that the NP treatment produced 9.5 t/ha and further addition of 150 kg K2O/ha increased the average yield to 10.4 t/ha (9.4%). The added net benefit due to K was US$174/ha. If calculated over the full 67 ha of demonstration sites, K increased paddy production by 60.3 t and increased net income by US$11,680.
Field trials for wheat, Chinese cabbage, and onion determined that 225-225-150 kg/ha produced the highest yields for wheat (7.1 t/ha), Chinese cabbage (72.3 t/ha), and onion (30.3 t/ha). Wheat, Chinese cabbage, and onion yields were reduced by 32%, 33%, and 33% without N; reduced 10%, 7%, and 6% without P; and reduced 7%, 7%, and 5% without K, respectively.
Huinong County: The K rate studies for onion determined that 225 kg K2O/ha provided the highest yield of 34.5 t/ha, which was 14% higher than the - K treatment, returning a net benefit of US$557/ha; in Chinese cabbage, 150 kg K2O/ha produced the highest yield of 75.3 t/ha, which was 17% higher than the - K treatment, returning a net benefit of US$371/ha.
Ten large field demonstrations covering about 14 ha determined that 150 kg K2O/ha increased wheat yield by an average of 7%, Chinese cabbage by 12%, sunflower by 4%, and onion by 12%. Ningxia-NMS02