Effects of Neem-Based Organic Fertilizer, NPK and Their Combinations on Soil Properties and Growth of Okra (Abelmoschus esculentus) in a Degraded Ultisol of Calabar, Nigeria

A field experiment was conducted at the University of Calabar Teaching and Research Farm to
evaluate the effects of neem-based organic fertilizer, NPK and their combinations on soil chemical
properties and growth of okra (Abelmoschus esculentus) on a degraded Ultisol Calabar. The
experiment was laid out in a randomized complete block design with three replications comprising of
six treatments. The treatments were control (no amendment), sole NPK 20:10:10 fertilizer and
neem–based organic fertilizer applied at 120 kg N/ha, combinations of 60 kg N/ha NPK+ 60 kg N/ha
Neem, 90 kg N/ha NPK + 30 kg N/ha Neem and 30 kg N/ha NPK + 90 kg N/ha Neem. Results
showed that the soil chemical properties were influenced significantly (P