Nutrient management and balanced fertilization on main crops in Qinghai province


28 Jan 2008

2007 Annual Interpretive Summary

Nutrient Management and Balanced Fertilization in Qinghai, 2007

In 2007, work focused on nutrient management and balanced fertilization studies in potato, rapeseed, horsebean, and vegetables in Xining City and Huzhu and Ledu Counties. Field demonstrations and farmer training were also carried out.

The irrigated potato trial in Xining indicated that balanced use of NPK of 158-75-135 kg N-P2O5-K2O/ha increased yield by 22%, 9%, 11%, and 12%, resulting in US$171 to US$358/ha more income, compared with the - N, - P, - K, and farmer practice (240-52-90 kg/ha), respectively.

Different varieties of rapeseed showed great variation in nutrient response. Application of 150-120-105 kg/ha increased yield of Qingza No. 3 by 84%, Qingyou No. 305 by 75%, and Qingyou No. 303 by 120% if compared with the zero fertilizer check (CK). An “optimum” (OPT) experiment on rapeseed in Huzhu determined that application of 125-75-135 kg/ha could produce 333, 900, 867, and 617 kg/ha, or 7 to 22% more yield and US$177 to US$517/ha more income, than the - N, - P, - K, and farmer practice treatment, respectively.

A K study on broadbean determined that application of 75 to 300 kg K2O/ha co-applied with 86-72 kg N-P2O5/ha could increase yield by 2 to 24% compared to the - K treatment. Application of 225 kg K2O/ha produced the highest yield of 4,200 kg/ha and best income of US$242/ha.

Experiments on garlic in Ledu found 450-120-225 kg/ha produced 4,872, 616, and 6,661 kg/ha, or 11%, 1%, and 16% more yield, as well as US$1,083, US$142, and US$1,509/ha more income compared to the - N, - P, and - K treatments, respectively.

Potassium application increased yield of green onion in Huzhu by 3 to 24%. The highest yield of 121 t/ha, and net benefit of US$1,352/ha, was obtained using 150 kg K2O/ha along with 428-43 kg N-P2O5/ha and 30 t farmyard manure. Qinghai-NMBF