Growing corn and soybean in acid soils requires lime application to raise the soil pH to reduce the aluminum toxicity and to add the nutrients calcium and magnesium. The residual effect of liming may last for several years of successive cropping. To evaluate this effect, an experiment was carried out in a Low Humic Gley soil in the EMBRAPA Cerrados Research Center, with the broadcasting application of lime levels of 0, 2, 4, 6 and 8 t ha-1, beginning in September, 1986. From September 1990, corn and soybean were sequentially cropped for seven years. Grain yield showed a significant response of corn and soybean to lime up to the third crop and of soybean in the fifth crop, from the 2 t ha-1 lime level upwards. Corn response to liming in the fourth and in the sixth crop was significant, respectively, from the 4 and 6 t ha-1 lime levels upwards. Maximum relative grain yield as an average for the four corn crops and three soybean crops was obtained, respectively, at a soil base saturation of 42% and 38%. From the fourth year to the tenth year after liming, the average annual decrease of exchangeable calcium + magnesium in the liming treatments was about 2 mmol c dm-3.
Zea mays; Glycine max; liming; Zea mays; Glycine max; lowland soils