Influence of Soil Amendment with Poultry Droppings on the Soil Properties and Productivity of Cucumbers (cucumis Sativus L.) on a Degraded Ultisol in Nsukka Area, Southeast Nigeria

Poultry manure (PM) input is globally utilized for enhancing and maintaining soil fertility in vegetable farming. In many tropical regions, however, ‘site’ specific PM rate for optimum crop yield is lacking. A three-year continuous cucumber cultivation with 0, 10, 20 and 30 t/ha PM rates in three replicates, were arranged in RCBD on an Ultisol. Soil physicochemical properties and cucumber yield responses to PM input rates were evaluated. The study soil was strongly acid and low in OC, N and exchangeable cations concentrations. The 20 and 30 t/ha PM input improved macro-aggregate stability by 91 and 99 %, respectively, and accordingly, increased the aggregates mean weight diameter. Poultry manure rates showed a lacking effect on cucumber length and girth, but the 20 and 30 t/ha PM rates significantly increased the number and weight of cucumber fruits in the first and third cropping years. Accordingly, the rates produced 10.53 t/ha cucumber fruits, corresponding to a three-fold yield increase. The overall soil chemical response to PM rates was a function of the PM quality. While improved P retention with 20 and 30 t/ha PM rates cut across the three cropping years, a significant increase in soil pH, Ca and K status was also evident with these rates in the third year. Also, the soil pH, C/N, P, Ca and K correlated positively to the number and weight of cucumber fruits. Based on ‘agronomic’ influence and convenience, 20 t/ha PM rate is therefore recommended for maintaining optimum cucumber yield in Ultisols.