The Effect of Tillage on Soil Physical and Chemical Properties and Yield of Ginger

Five tillage methods were compared during the seasons of 2014–2016 with reference to their effects on soil physical and chemical properties and fresh rhizome yield of ginger (Zingiber officinale Roscoe) on an Alfisol at Owo, southwest Nigeria. The tillage methods were: zero tillage (ZT), manual ridging (MR), manual mounding (MM), ploughing plus harrowing (P + H) and ploughing plus harrowing twice (P + 2H). P + 2H had higher soil bulk density than other tillage methods and resulted in lower soil OM, N, P, K, Ca and Mg and rhizome yield of ginger. ZT improved soil bulk density, moisture content, temperature, soil OM, N, P, K, Ca and Mg better than other tillage methods and resulted in higher plant height and rhizome yield of ginger compared with other tillage treatments. Results of multiple regressions revealed that bulk density and moisture content significantly influenced the yield of ginger. Compared with MR, MM, P + H and P + 2H, and averaged across years, ZT increased rhizome yield of ginger by 10.9, 11.5, 4.9 and 26.8%, respectively. P + 2H degraded soil quality and reduced rhizome yield of ginger significantly. ZT was found to be the most suitable for soil health and optimum yield and is therefore recommended for ginger cultivation

The Effect of Tillage on Soil Physical and Chemical Properties and Yield of Ginger

Five tillage methods were compared during the seasons of 2014–2016 with reference to their effects on soil physical and chemical properties and fresh rhizome yield of ginger (Zingiber officinale Roscoe) on an Alfisol at Owo, southwest Nigeria. The tillage methods were: zero tillage (ZT), manual ridging (MR), manual mounding (MM), ploughing plus harrowing (P + H) and ploughing plus harrowing twice (P + 2H). P + 2H had higher soil bulk density than other tillage methods and resulted in lower soil OM, N, P, K, Ca and Mg and rhizome yield of ginger. ZT improved soil bulk density, moisture content, temperature, soil OM, N, P, K, Ca and Mg better than other tillage methods and resulted in higher plant height and rhizome yield of ginger compared with other tillage treatments. Results of multiple regressions revealed that bulk density and moisture content significantly influenced the yield of ginger. Compared with MR, MM, P + H and P + 2H, and averaged across years, ZT increased rhizome yield of ginger by 10.9, 11.5, 4.9 and 26.8%, respectively. P + 2H degraded soil quality and reduced rhizome yield of ginger significantly. ZT was found to be the most suitable for soil health and optimum yield and is therefore recommended for ginger cultivation

Potassium iodide influence on iodine-leaf concentration and growth of amaranth (Amaranthus cruentus L.).

Low iodine content in soils is a common feature in lowland and in mountainous regions far from oceans. The diets of the people living in these regions are often deficient in dietary iodine, resulting in chronic iodine deficiency syndrome, goiter, hearing loss and other debilitating diseases. A field experiment was conducted at the Teaching and Research Farm, University of Ilorin, Nigeria during the 2017 and 2018 cropping seasons, to evaluate the response of amaranths to iodine enrichment using an agronomic approach. The trial consisted of potassium iodide (KI) applied as foliar spray at 0, 3.5, 7, 10.5, 14 kg ha-1 and soil applied at the rates of 4, 8, 12 and 16 kg ha-1. These treatments were in four replicates laid out in a randomized complete block design. Data were collected on plant height, number of leaves, leaf area, crop growth rate, yield and iodine-leaf concentration. The data were subjected to analysis of variance (ANOVA) followed by mean separation using Duncan`s Multiple range test p 0.05. The results indicated that the use of KI improved the growth of amaranthus at the low level of application, but foliar application at 10.5 and 14 kg ha-1 yielded the highest iodine leaf concentration. Although application of iodine in amaranthus improved iodine leaf concentration, there was a colour change at higher rates of application which may affect the acceptability of the vegetable by consumers

Soil Properties, Growth, Fruit Yield, Mineral, Lycopene and Vitamin C Contents of Tomato (Lycopersicon esculentum Mill) Grown with Green Manures and NPK Fertilizer

Green manures as an alternative to inorganic fertilizer offer considerable potential as a source of plant nutrients and organic matter. Hence, field experiments were carried out during 2015 and 2016 cropping seasons to compare impacts of green manures (GM) and NPK 15-15-15 fertilizer on soil properties, growth, fruit yield, mineral, lycopene and vitamin C contents of tomato (Lycopersicon esculentum Mill). The GM from green tender stems and leaves of: Pawpaw (Carica papaya L.), Neem (Azadirachta indica A. Juss.), Moringa (Moringa oleifera Lam.) and Gliricidia (Gliricidia sepium (Jacq.) Kunth ex Walp.) were applied at 5 t ha-1, and the NPK fertilizer was applied at 300 kg ha-1. Plots without fertilizer were used as a control. Application of GMs reduced soil bulk density and increased soil organic matter (OM), N, P, K, Ca, Mg, growth and fruit yield of tomato compared with the control. The NPK fertilizer had no effect on soil bulk density and soil OM, and increased soil N, P, K, Ca, Mg, growth and fruit yield of tomato compared with the control. Gliricidia increased growth and fruit yield of tomato compared with NPK fertilizer and other GMs. The GMs and NPK fertilizer increased mineral, lycopene and vitamin C contents in the tomato fruits compared with the control. Moringa produced higher K, Ca, Fe, Zn, Cu, lycopene and vitamin C contents compared with other GMs and NPK fertilizer. Use of GM has potential to improve soil properties, and growth, fruit yield and nutritional contents of tomato than does NPK fertilizer. The Gliricidia treatment best improved soil properties and tomato productivity as indicated by the benefit-cost ratio. For those growing tomato for fruit quantity Gliricidia is recommended as green manure. For those that desire fruit quality Moringa is recommended as green manure

Soil Properties, Growth, Fruit Yield, Mineral, Lycopene and Vitamin C Contents of Tomato (Lycopersicon esculentum Mill) Grown with Green Manures and NPK Fertilizer

Green manures as an alternative to inorganic fertilizer offer considerable potential as a source of plant nutrients and organic matter. Hence, field experiments were carried out during 2015 and 2016 cropping seasons to compare impacts of green manures (GM) and NPK 15-15-15 fertilizer on soil properties, growth, fruit yield, mineral, lycopene and vitamin C contents of tomato (Lycopersicon esculentum Mill). The GM from green tender stems and leaves of: Pawpaw (Carica papaya L.), Neem (Azadirachta indica A. Juss.), Moringa (Moringa oleifera Lam.) and Gliricidia (Gliricidia sepium (Jacq.) Kunth ex Walp.) were applied at 5 t ha-1, and the NPK fertilizer was applied at 300 kg ha-1. Plots without fertilizer were used as a control. Application of GMs reduced soil bulk density and increased soil organic matter (OM), N, P, K, Ca, Mg, growth and fruit yield of tomato compared with the control. The NPK fertilizer had no effect on soil bulk density and soil OM, and increased soil N, P, K, Ca, Mg, growth and fruit yield of tomato compared with the control. Gliricidia increased growth and fruit yield of tomato compared with NPK fertilizer and other GMs. The GMs and NPK fertilizer increased mineral, lycopene and vitamin C contents in the tomato fruits compared with the control. Moringa produced higher K, Ca, Fe, Zn, Cu, lycopene and vitamin C contents compared with other GMs and NPK fertilizer. Use of GM has potential to improve soil properties, and growth, fruit yield and nutritional contents of tomato than does NPK fertilizer. The Gliricidia treatment best improved soil properties and tomato productivity as indicated by the benefit-cost ratio. For those growing tomato for fruit quantity Gliricidia is recommended as green manure. For those that desire fruit quality Moringa is recommended as green manure

IMPACT OF POULTRY MANURE AND NPK FERTILIZER ON SOIL PHYSICAL PROPERTIES AND GROWTH AND YIELD OF CARROT

A field experiment was conducted in the forest-savanna transition zone of Nigeria from May to July 2014 and September to November 2015 to determine the impacts of poultry manure (PM) and NPK fertilizer on soil physical properties, and growth and yield of carrot (Daucus carota L.). The five treatments included no manure or fertilizer (control); 10, 20, and 30 megagrams (Mg)·ha-1 of PM; and 300 kg·ha-1 of 15 N-15 P-15 K fertilizer. All levels of PM reduced soil bulk density and temperature, and improved total porosity and moisture content compared to the NPK fertilizer and the control. Plant height, number of leaves, root diameter, root length, and fresh root yield in the PM and NPK fertilizer treatments were improved compared to the control. Growth and yield parameters of carrot plants treated with 20 and 30 Mg·ha-1 PM were higher than the other treatments. The 10 Mg·ha-1 PM and NPK fertilizer treatments produced similar growth and yield responses. There was an interaction for year (Y) × fertilizer (F) on plant height, number of leaves, and fresh root yield. Relative to the control 10, 20, or 30 Mg·ha-1 PM and NPK fertilizer increased fresh root yield of carrot by 39.9%, 62.0%, 64.9%, and 37.3%, respectively. The 20 Mg·ha-1 PM treatment best improved soil properties and carrot productivity as indicated by the benefit-to-cost ratio

Effects of biochar and poultry manure on soil characteristics and the yield of radish

Studies on the effect of biochar and poultry manure on soil properties and radish productivity is rare, hence, field experiments were conducted over two years, 2015 and 2016, to evaluate the effects of biochar (B) and poultry manure (PM) on soil properties, leaf nutrient concentrations and root yield of radish (Raphanus sativus L.). Each year, the experiment consisted of 3 × 3 factorial combinations of biochar (0, 25 and 50 t ha−1) and poultry manure (0, 2.5 and 5.0 t ha−1). Application of B and PM alone, and in combination, improved soil physical and chemical properties, leaf nutrient concentrations and yield components of radish. In 2016, the application of B alone increased the soil pH and concentrations of organic matter, N, P, K, Ca and Mg, as well as leaf nutrient concentrations and yield of radish, but in 2015 it only increased soil pH and organic matter and not leaf nutrient concentrations and yield. In both years, the application of B significantly influenced the root length of the radish. In both years, there was a significant interaction effect of biochar and poultry manure (B × PM) and this was attributed to the ability of the B to increase the efficiency of the utilization of the nutrients in the PM. The combination of 50 t ha−1 B and 5 t ha−1 PM (B50 + PM5) resulted in the highest radish yield. Averaged over the two years, (B50 + PM5) increased the root weight of radish by 192, 250 and 257% compared with biochar alone at 50 t ha−1, biochar alone at 25 t ha−1 and no application of B or PM (control). Therefore, for a short season crop like radish the expected benefit of the biochar alone without the addition of poultry manure may not be achieved within the first year

Poultry and Green Manures Effects on Soil Properties, and Sorghum Performance, and Quality

Nigeria’s savanna soils where sorghum (Sorghum bicolor L. Moench) is majorly produced are characterized by a lot of challenges. Hence, field experiments were conducted in 2018 and 2019 on sole and combined effects of Panicum maximum, Tithonia diversifolia, and poultry manure (PM) on soil physico-chemical properties, growth, yield, and proximate contents of sorghum. The treatments were: 10 t ha⁻¹ Tithonia leaves, 10 t ha⁻¹ Panicum leaves, 10 t ha⁻¹ PM, 5 t ha⁻¹ Tithonia leaves + 5 t ha⁻¹ Panicum leaves, 5 t ha⁻¹ Tithonia leaves + 5 t ha⁻¹ PM, 5 t ha⁻¹ Panicum leaves + 5 t ha⁻¹ PM (Panicum + PM), control. The treatments were arranged in a randomized complete block design with three replications. Green manures and PM either sole or combined reduced sorghum’s grain fiber, fat and carbohydrate, soil bulk density and increased porosity, moisture content, soil organic matter (SOM), nutrient content, growth, yield, and moisture, ash and protein contents of sorghum compared with the control. When manures were combined, Panicum + PM has the highest value of these parameters but the least of grains fiber, fat, carbohydrate, and soil bulk density. The increased growth, yield, and quality of sorghum credited to Panicum + PM was owed to improved soil physical and chemical properties and also due to the fact that slowly decaying Panicum may allow retention of released nutrients from rapidly decomposing PM within the rooting zone. The study revealed that locally available organic materials can be recycled in improving soil and crop productivity especially when they are combine

Impacts of poultry manure and biochar amendments on the nutrients in sweet potato leaves and the minerals in the storage roots

Abstract Poultry manure (PM) has demonstrated its potential to enhance crop nutritional quality. Nevertheless, there remains a dearth of knowledge regarding its synergistic effects when combined with wood biochar (B) on the nutrient concentrations in sweet potato leaves (Ipomoea batatas L.) and the mineral content stored in sweet potato storage roots. Hence, a two-year field trial was undertaken during the 2019 and 2020 cropping seasons in southwestern Nigeria, spanning two locations (Owo—site A and Obasooto—site B), to jointly apply poultry manure and wood biochar as soil amendments aimed at enhancing the nutritional quality of sweet potato crop. Each year, the experiment involved different combinations of poultry manure at rates of 0, 5.0, and 10.0 t ha−1 and biochar at rates of 0, 10.0, 20.0, and 30.0 t ha−1, organized in a 3 × 4 factorial layout. The results of the present study demonstrated that the individual application of poultry manure (PM), biochar (B), or their combination had a significant positive impact on the nutrient composition of sweet potato leaves and minerals stored in the sweet potato storage roots, with notable synergistic effects between poultry manure and biochar (PM × B) in enhancing these parameters. This highlights the potential of biochar to enhance the efficiency of poultry manure utilization and improve nutrient utilization from poultry manure. The highest application rate of poultry manure at 10.0 t ha−1 and biochar at 30.0 t ha−1 (PM10 + B30), resulted in the highest leaf nutrient concentrations and mineral composition compared to other treatments at both sites. Averaged over two years, the highest application rate of poultry manure at 10.0 t ha−1 and biochar at 30.0 t ha−1 (PM10 + B30) significantly increased sweet potato leaf nutrient concentrations: nitrogen by 88.2%, phosphorus by 416.7%, potassium by 123.8%, calcium by 927.3%, and magnesium by 333.3%, compared to those in the control (PM0 + B0). The same treatment increased the concentration of sweet potato root storage minerals: phosphorus by 152.5%, potassium by 77.4%, calcium by 205.5%, magnesium by 294.6%, iron by 268.4%, zinc by 228.6%, and sodium by 433.3%, compared to the control. The highest application rate of poultry manure at 10.0 t ha−1 and biochar at 30.0 t ha−1 yielded the highest economic profitability in terms of gross margin (44,034 US$ha−1), net return (30,038 US$ ha−1) and return rate or value-to-cost ratio (VCR) (263). The results suggested that the application of poultry manure at 10 t ha−1 and biochar at 30 t ha−1 is economically profitable in the study areas and under similar agroecological zones and soil conditions