RESPONSE OF MAIZE TO PHOSPHORUS FROM FERTILIZER AND CHICKEN MANURE IN A SEMI-ARID ENVIRONMENT OF SOUTH AFRICA

Abstract

SUMMARYChicken manure is a potential source of plant available phosphorous (P) and this field study explored its use for dry land maize production in a soil with very low inherent P levels. The treatments consisted of applying 0, 20, 40 and 80 kg P ha−1each from chicken manure (2.3% P), inorganic fertilizer (single super phosphate, 10.5% P) and a combination of manure and fertilizer. The treatments were replicated four times in a randomized complete block design over two crop seasons. The results revealed that maize growth and yield responded to the P from both manure and fertilizer compared to the control. There were significantly (p< 0.05) taller plants and yield (grain and biomass) in maize supplied with P than control. At each level of P application however, the response was higher for fertilizer than manure. The combination of manure and inorganic fertilizer produced results that were in the middle. There were strong indications that application of chicken manure was associated with increased lodging possibly due to the additional N in the manure, attack by stalk borer (Buseola fusca) and reduced seedling emergence. The application of chicken manure on the other hand led to increased pH and greater residual P content of the soil than fertilizer. It is concluded that chicken manure presents a viable option for supplying P to sustain maize crops in the smallholder farming sector of South Africa and its management warrants further investigation in view of the potential adverse impacts on soil and water resources that can accrue when large amounts are used for a long period.