Responses of three different corn cultivars to different fertilizer treatments


30 Jan 2007

2006 Annual Interpretive Summary

Responses of Corn Cultivars to Fertilizer in Guizhou, 2006

Corn is both a staple food and critical feedstuff in the mountainous region of Guizhou Province. The annual growing area is estimated at 707,000 ha. In the past, fertilizer research on corn has been general, lacking cultivar and site-specific fertilizer schemes. The objectives of this project were to study the responses of three corn cultivars (cv. 2599, Qiandan21 and Mobai94) to different NPK fertilizer at three locations, and to verify the optimal fertilizer rates for corn production in the province. The first two are considered high yielding cultivars and the third one is a low yielding cultivar used in more remote areas. Five fertilizer treatments included a balanced optimum (OPT), OPT-N, OPT-P, OPT-K and OPT+ manure. The OPT consisted of 207-90-75 kg N-P2O5-K2O/ha.

The three culitvars responded similarly to fertilization. The cultivars were most sensitive to N omission, followed by K omission, then P omission. Averaged over sites, the high yield corn cultivars produced much higher seed yields of 8,286 kg/ha (2599) and 8,525 kg/ha (Qiandan21) compared to the lower yielding cultivar which produced 5,550 kg/ha. The OPT treatment produced 3,215 kg/ha (86%), 2,537 kg/ha (58%), and 731 kg/ha (12%) more yield than the treatments omitting N, K, and P treatments for the high yield cultivar 2599, respectively. Qiandan21 behaved very similarly to cultivar 2599. Responses with the low yielding cultivar were comparatively larger as the OPT produced 2,733 kg/ha (135%), 1,260 kg/ha (48%), and 901 kg/ha (15%) more yield than the treatments omitting N, K, and P, respectively. All three cultivars responded to the OPT+manure treatment, which produced an additional 3% to 8% more yield.

Yields for all three cultivars varied considerably from one location to another. For example, the maximum yield for cultivar 2599 ranged between 6,315 to 8,286 kg/ha. Yields were significantly affected by differences in weather, soil fertility, and other environmental factors. More study is required to determine and verify location- and cultivar-specific fertilizer rates before any large-scale adoption can be considered. Guizhou-BFDP-06