Effects of Green Manures and NPK Fertilizer on Soil Properties, Tomato Yield and Quality in the Forest-Savanna Ecology of Nigeria

Abstract

SUMMARYGreen manures (GM) as an alternative to inorganic fertilizer offer considerable potential as a source of plant nutrients and organic matter (OM). Hence, field experiments were carried out during 2015 and 2016 cropping seasons to compare impacts of GM and NPK (15:15:15) fertilizer on soil properties, growth, fruit yield, mineral, lycopene and vitamin C contents of tomato (Lycopersicon esculentum Mill). GMs were composed by green tender stems and leaves of pawpaw (Carica papaya L.), neem (Azadirachta indica A. Juss.), moringa (Moringa oleifera Lam.) or gliricidia (Gliricidia sepium (Jacq.) Kunth ex Walp.) and applied at 5 Mg ha−1, whereas NPK was applied at 300 kg ha−1 and there was a no fertilizer plot (control). Application of GMs reduced soil bulk density and increased soil OM, N, P, K, Ca, Mg, growth, number of fruits and fruit yield of tomato compared with the control. NPK fertilizer had no effect on soil bulk density and soil OM, but it increased soil fertility and tomato yield as compared with the control. When comparing treatments, the highest tomato yield and best cost:benefit ratio were obtained with gliricidia as GM. The GMs and NPK fertilizer increased mineral, lycopene and vitamin C contents in tomato fruits and the highest K, Ca, Fe, Zn, Cu, lycopene and vitamin C contents in tomato fruits were found with moringa as GM. Our results revealed that GM has potential to improve soil properties, tomato yield and quality, being an alternative for cropping management.

Green manures and poultry feather effects on soil characteristics, growth, yield, and mineral contents of tomato

“…The interactive effect of year and amendment (Y × A) was significant for all growth and yield parameters, this was adduced to higher soil chemical properties in the second year of cropping tomato which is attributed to improved cation exchange capacity (Agbede et al, 2018), therefore, the improved growth and yield in the second year was due to improved nutrient availability due to residual effect from the first year and the subsequent application of the organic amendment in the second year. The addition of fresh manures to the soil in the second year may provide a fresh carbon source for microorganisms, enhancing the biological activities in the soil, and thus accelerating soil nutrient release (Xia et al, 2014), and therefore better growth and yield.…”

“…Chemical fertilizers can be used for improving soil fertility and crop yield, but their use especially in Nigeria is limited by scarcity and cost. Other problems associated with the use of chemical fertilizers are acidity, nutrient imbalance, (Agbede et al, 2018) and inability to improve aggregate stability by increasing soil organic matter. Organic amendments can be a cheap and readily available source of organic matter for sustaining both the physical and chemical soil characteristics and crop yield.…”

Effects of Different Rates of Poultry Manure and Split Applications of Urea Fertilizer on Soil Chemical Properties, Growth, and Yield of Maize

“…Maize is a nutrient demanding crop and therefore adequate and balanced nutrient supply is important in its growth and production. The use of chemical fertilizer has been reported [ 5 ] to increase crop yields, but in Nigeria, its use is limited by high cost, scarcity during the time of its need (planting season), soil acidity, and nutrient imbalance. Because of these, the use of organic manure like poultry manure (PM) was found useful in increasing crop production.…”

Effects of biochar and poultry manure on soil properties, growth, quality, and yield of cocoyam (Xanthosoma sagittifolium Schott) in degraded tropical sandy soil

“…Disturbed soil samples were also collected on an individual plot basis at harvest of cocoyam from 0-15 cm depth in 2017 (first crop) and 2018 (second crop) and similarly analyzed for chemical properties. The procedures for the analysis of soil OC, N, P, K, Ca, Mg, and pH are described in detail by Carter and Gregorich (2007) and Agbede et al (2019).…”

“…In each year and after 2 months of planting the cocoyam cormels, soil physical properties were evaluated in all plots at 2-month intervals on four occasions and averaged. Five samples (4 cm diameter, 0-15 cm depth) were collected from each plot using a steel coring tube and were used for the evaluation of bulk density, total porosity, and gravimetric moisture content after ovendrying at 100°C for 24 h (Agbede et al, 2019).…”