Pyrolyzed agricultural wastes for improving degraded soil, nutrient use efficiency and growth performance of maize

The need for cheap and affordable alternate sources of plant nutrient inputs to boost the nutrient level of degraded arable farmlands has been a major concern for soil scientists. In 2018, a field study was carried out under rain-fed conditions to evaluate the effect of palm waste biochar (PWB), poultry litter biochar (PLB) and inorganic fertilizer on the properties of soil, N and P use efficiency on a sandy Ultisol. The treatments consisted of T 1 (control), T 2 (625 kg ha -1 NPK fertilizer), T 3 (10 t ha -1 PWB + 625 kg ha -1 NPK fertilizer), T 4 (10 t ha -1 PLB + 625 kg ha -1 NPK fertilizer), T 5 (5 t ha -1 PWB + 5 t ha -1 PLB + 625 kg ha -1 NPK fertilizer) and T 6 (10 t ha -1 PWB+10 t ha -1 PLB + 625 kg ha -1 NPK fertilizer). These treatments were arranged in a randomized complete block design and replicated three times. Data were analysed using Analysis of Variance (ANOVA) and significant effects among treatment means were determined using Fishers Least Significant Difference (F-LSD) at a 5% probability level. Results showed that biochar application significantly ( p = 0.05 ) reduced soil bulk density by 9.9%, increased soil organic matter by 28.4%, total exchangeable bases by 34.8% and raised soil pH by 19.2%. The number of leaves, plant height and leaf area of maize were significantly higher in the amended plots than that of the control plots after six weeks of planting. Plots amended with 10 t ha -1 PLB+625kg ha -1 NPK fertilizer had the highest grain and fresh cob yield of 3.08 t ha -1 and 7.53 t ha -1 , respectively, while the least values were obtained in the control plots (2.18t ha -1 and 4.03 t ha -1 , respectively). The highest values of nitrogen uptake (70.84 kg ha -1 ), physiological efficiency of (27.47 kg ha -1 ), phosphorus uptake (78.54 kg ha -1 ), phosphorus use efficiency (80.14%), agronomic efficiency of N (9.6 kg ha -1 ), agronomic efficiencies of P(22.02 kg ha -1 ), partial factor productivity of N (32.85 kg ha -1 ) and P (75.34 kg ha -1 ) as well as N physiological efficiency (30.6 kg ha -1 ) were obtained in plots amended with 10 t/ha PLB + 625 kg ha -1 NPK fertilizer. Therefore, application of 10 t ha -1 PLB + 625 kg ha -1 NPK fertilizer is recommended for improved N and P use efficiencies, N and P uptakes, yield performance of maize and improvement in the soil properties of a degraded acidic soil.