Effect of liming an ultisol in Ghana on maize (zea mays l.) yield and some soil properties

FIELD AND GREENHOUSE EXPERIMENTS WERE CONDUCTED TO STUDY THE EFFECT OF LIME APPLICATION ON MAIZE GROWTH AND SOME SOIL PROPERTIES. THE WORK WAS CONDUCTED ON AN ULTISOL IN THE FOREST REGION OF GHANA. FIELD RESULTS SHOWED THAT LIMING DID NOT HAVE AN EFFECT ON BICARBONATE EXTRACTABLE P (OLSEN), 0.1M HC1 EXTRACTABLE ZN, AND CEC AN EXCHANGEABLE MG OF THE TOP SOIL. PH AND EXCHANGEABLE CA INCREASED WITH INCREASED LIME APPLICATION. ON THE OTHER HAND, THE SUBSOIL WAS NOT AFFECTED BY LIMING THE TOP SOIL, WHICH MAY INDICATE LITTLE OR NO LEACHING OF THE CA. LIME APPLICATION DID NOT SIGNIFICANTLY INCREASE MAIZE GRAIN YIELD IN BOTH THE MAJOR AND MINOR SEASON. THE FIRST INCREMENT OF LIME (0.5 T/HA) INCREASED GRAIN YIELD ECONOMICALLY AND THAT SUBSEQUENT LEVELS DID NOT, WITH A GREAT YIELD DEPRESSION AT THE HIGHEST LIME RATE (4 T/HA). SHORT TIME GREENHOUSE EXPERIMENTS SHOWED THAT INCREASED LIME APPLICATION SIGNIFICANTLY INCREASED THE BICARBONATE EXTRACTABLE P, 0.5M CACL2 PH 1.5 EXTRACTABLE SIO2, PH, EXCHANGEABLE CA AND ALSO EFFECTIVE CEC IN BOTH THE TOP AND SUBSOIL TREATMENTS. THE RESULTS SHOWED THAT THE EFFECT OF EXCESS LIME APPLICATION WAS TO DEPRESS MAIZE GROWTH AND THAT THE EFFECT WAS ACCENTUATED WHEN THE SOIL HAD A LOW BUFFERING CAPACITY, SUCH AS THE SUBSOIL IN THE PRESENT STUDY. RESPONSE OF MAIZE GROWTH TO P APPLICATION WAS SIGNIFICANT, AND THE EFFECT WAS GREATEST AT THE LOWEST P RATE (45 KG P/HA), ALTHOUGH P APPLICATION DID NOT ALLEVIATE THE DEPRESSING EFFECT OF OVERLIMING THE SOILS. IN FACT, HIGHEST P AND LIME RATES CAUSED ZN DEFICIENCY SYMPTOMS. NUTRIENT UPTAKE WAS GREATLY INCREASED WITH INCREASED P RATES, WHEREAS LIME DEPRESSED MOST OF THE NUTRIENTS EXCEPT CA UPTAKE. ZN APPLICATION INCREASED MAIZE GROWTH SIGNIFICANTLY, MORE ESPECIALLY WHEN LIME WAS APPLIED. ONE WOULD BE LED TO CONCLUDE THAT SINCE THERE WAS A MODEST RESPONSE TO THE FIRST INCREMENT OF LIME IN THE FIELD EXPERIMENT, THE LIME REQUIREMENT FOR KUMASI SOIL IS LOW.