Mechanism(s) Underlying Interactions Between Cattle Manure and Mineral Fertilizer in a Maize Field Soil in Ghana

A 70-day laboratory incubation study was conducted to unravel the mechanism(s) underlying synergistic interactions between organic and inorganic nutrient inputs to the soil. Soil from a maize farmer's field at Kpongu in the Upper West Region of Ghana was amended with a factorial combination of 0, 50% and 100% levels of the recommended rates (RR) of inorganic fertilizer and cattle manure and incubated at room temperature in plastic cups. Deionized water was added to maintain soil moisture at 70% field capacity throughout the incubation period. Cups were covered with gas-permeable parafilm. Soil sampling was done at 7, 28, 42, 56 and 70 days after incubation. The soil was analyzed for available phosphorus, organic carbon, microbial biomass carbon, nitrates, ammonium, soil urease activity, iron, and copper at each sampling. The addition of 100% RR NPK + 50% RR manure often results in higher amounts of the measured parameters,synergistic interactions and supply of nutrients to the soil, with longer residual effects. While all the under-studied mechanisms (improved nutrient synchrony, priming effects, general fertility improvement fertility) contribute to synergistic interactions, the improved nutrient synchrony mechanism is the most prominent. Farmers can therefore manage the timing of the nutrient inputs well to capitalize on this mechanism for improved soil fertility.&nbsp

Manure Management, Quality and Mineralization for Sustaining Smallholder Livelihoods in The Upper East Region of Ghana

A survey was conducted in the Upper East region of Ghana to seek information on the fertility status of the soils, manure production, its management options and nutrient concentration that could be associated with quality. Analysis of soils from farmers’ fields showed that the soils are coarse textured, with low exchange capacity and organic matter contents. Available P in particular was very low with most of the soils having values less than 6.00 ppm. Four main types of cattle rearing systems were encountered; the field, kraal, compound and intensive. Fresh manure samples from each of these systems were collected air dried and analysed in the laboratory using standard protocols. The N and P contents of the manure ranged from 0.52 % to 1.14 %, and 0.28 % to 0.76 % respectively, which were below the critical levels for net mineralization. Polyphenol contents on the other hand were lower than the critical value of 4 %. Decomposition and nutrient release of the manure showed immobilization of total N during the first four weeks, suggesting the need to improve the quality by composting or applying it in combination with mineral fertilizers.Keywords: Crop production, fertilizer value, nutrient release, soil fertility

On-farm evaluation and determination of sources of variability of soybean response to Bradyrhizobium inoculation and phosphorus fertilizer in northern Ghana

Open Access Article; Published online: 14 Aug 2018.Soybean yields on smallholder farms in sub-Sahara Africa (SSA) are far below the potential yield thus creating a huge yield gap. Interventions are thus needed to bridge this yield gap and ascertain the factors influencing the yield variation. This study evaluated the on farm response of soybean to rhizobia inoculation and or mineral P fertilizer in Northern and Upper West regions of Ghana in a single non-replicate trial using four treatments: no input (control), TSP fertilizer (P), rhizobia inoculant (I) and TSP plus inoculant (P + I). In addition, the study sought to develop a robust approach for determining responsiveness and non-responsiveness using agronomic and economic indices. The results showed that the average grain yield of plots that received P or I were higher than control plots. Higher grain yield responses were however, obtained by the plots that received combined application of P and Bradyrhizobium inoculant. Grain yield response in the Northern region was higher than in the Upper West region. Response to P and or I were highly variable within and between locations. The cumulative rainfall and some soil factors including soil nitrogen, phosphorus, soil type, organic carbon, pH and texture explained about 42–79% of these variations in soybean grain yield. The agronomic approach for determining responsive and non-responsiveness revealed that 17–40 % and 6–17% of the locations within the Northern and Upper West regions, respectively were responsive to P fertilization and/ or Bradyrhizobium inoculation. However, the economic approach indicated that 64–75% and 14–24% of the locations within the Northern and Upper West regions, respectively were responsive to P fertilization and Bradyrhizobium inoculation. The results imply that rhizobia inoculation is an effective strategy for increasing soybean yield and improving livelihood of smallholder farmers

Organic manure improves soybean response to rhizobia inoculant and p-fertilizer in northern Ghana

Open Access Journal; Published online: 04 Sept 2020Inherently low concentrations of soil nutrients and erratic rainfall pattern in sub-Sahara Africa limit soybean response to rhizobia inoculant and P-fertilizer. The study was conducted to: (i) improve soybean response to rhizobia inoculation and P-fertilizer through the addition of organic manure; (ii) enhance rain water use efficiency and (iii) determine the economic viability of combined application of the three factors in soybean cropping systems in the Northern region of Ghana. A factorial experiment with two levels of rhizobia inoculant, two levels of Phosphorus, two different kinds organic manure [fertisoil (a commercially prepared compost from urban waste, rice husks, of poultry manure and shea butter waste) and cattle manure] and a control arranged in randomized complete block design with three replications was established on farmers’ fields. The combined application of rhizobia inoculant, P-fertilizer, and organic manure markedly increased nodulation, shoot biomass, haulms, harvest index (HI), P agronomic efficiency (P-AE), and rain water use efficiency (RUE) compared to the control. The combined application of rhizobia inoculant, P-fertilizer, and fertisoil increased grain yield by four-folds whereas the combined application of rhizobia inoculant, P-fertilizer, and cattle manure increased grain yield by three- folds. Harvest index, P-AE, and RUE were relatively higher with the fertisoil treatment combinations than with the cattle manure combinations and the control treatment. The application of rhizobia inoculant, P-fertilizer in combination with fertisoil was profitable with VCR of 2 as compared to the combination of cattle manure which had a VCR of 0.40. The results showed that fertisoil offers a better option of improving soybean response to rhizobia inoculant and P-fertilizer; and has the potential to enhance rain water use efficiency. However, the long term benefit must be quantified

Combined application of inoculant, phosphorus and organic manure improves grain yield of cowpea

Published online: 01 Oct 2019Low concentrations of P and organic manure in savanna soils limit cowpea response to rhizobia. The study was conducted to determine the combined effect of P and organic manure on cowpea response to rhizobia in a factorial experiment arranged in randomized complete block design with three replications on smallholder farmers’ fields in northern Ghana in 2015. The factors were two levels of Bradyrhizobium inoculant, two levels of P fertilizer, three treatments of manure (fertisoil, cattle manure, and no manure). Addition of Bradyrhizobium inoculant to P and fertisoil significantly increased shoot biomass yield from 1677 kg ha−1 in the plots without Bradyrhizobium inoculation to 1913 kg ha−1. Likewise, the addition of Bradyrhizobium inoculant to P and cattle manure significantly increased shoot biomass from 1437 kg ha−1 to 1813 kg ha−1. Grain yield increases of 1427 and 1278 kg ha−1 were obtained over the control when either fertisoil or cattle manure and P, respectively, were added to Bradyrhizobium inoculant. The value cost ratio for adding Bradyrhizobium inoculant to phosphorus and fertisoil was two indicating that it could be attractive to risk-averse smallholder farmers. The study demonstrated the potential of the combined application of organic matter and P to improve cowpea response to Bradyrhizobium inoculation

Evaluation of medium-maturing soybean (Glycine max (L) Merrill) lines for their nitrogen fixation potentials

br>A field experiment was carried out to determine the nitrogen fixation ability of some soybean experimental lines and to determine the amount of residual nitrogen that could be made available to a succeeding arable crop. The study was undertaken at the Crops Research Institute, Fumesua, Kumasi. The experiment was laid out in a randomized complete block design with 3 replications. Each replication consisted of 10 plots which were randomly sown to a soybean line. The seeds were sown at a spacing of 75 cm between rows and 5 cm between plants. Data collected were nodule number per plant and nodule dry weight, number of pods per plant, number of seeds per pod, total seed yield, seed, residue and total nitrogen fixed by the soybean lines. The Total Nitrogen Difference method was used in determining the amount of N2 fixed. The results showed that all the lines nodulated freely with the naturalized rhizobia in the soil. There were significant differences, however, in the nodulation abilities of the lines. Number of nodules was negatively correlated with nodule dry weight (r=- 0.45). The amount of nitrogen fixed was positively correlated with total seed yield (r= 0.65). Line GMX 92-16-2M produced the greatest number of nodules but did not fix the greatest amount of nitrogen. Line GMX 92-6-10M left the greatest amount of nitrogen (10 kg N ha-1) in its residue. The results indicate that if farmers would grow this line, an amount of 10 kg N ha-1 would be made available to subsequent arable crop following harvesting

Is there a need for Bradyrhizobium yuanmingense and B. japonicum reinoculation in subsequent cropping seasons under smallholder farmers' conditions?

Published online: 10 April 2018.Reliable information on the persistence of rhizobium in soil in the absence of host between growing periods is important in deciding whether inoculation on the same plot in subsequent seasons is necessary. This study determined the survival of introduced rhizobium strains and predominant factors that influence the declining rates of their populations. Bradyrhizobium yuanmingense (BR 3267) and B. japonicum (USDA 110) were manually incorporated into soils at four different locations (Kpalga, Tanina, Tunayilli and Busa) in northern Ghana at 2.5 × 108 (log10 8.4) and 2.5 × 107 (log10 7.4) cells g−1 peat, respectively, per 6 m2. The populations of surviving cells were estimated at 0, 21, 42, 81, 142 and 296 days using the Most Probable Number (MPN) count technique. Several decline functions were applied to the data with hyperbolic regression function emerging as the option that provides the best fit for B. yuanmingense strain BR 3267 and B. japonicum strain USDA 110 at all locations. There was no significant difference in the declining rates between the different locations; however, there were differences in the declining rates for the sampling times. At 296 days, the numbers of surviving cells of B. yuanmingense strain BR 3267 and B. japonicum strain USDA 110 were log10 1.9 and log10 1.7, respectively. Native rhizobium population and soil moisture were the predominant factors that affected the survival of the introduced strains. It is evident from the studies that these strains can survive in sufficient numbers at least within a year; therefore, re-inoculation may not be necessary for a following season especially when using B. yuanmingense strain BR 3267

Nutrient release patterns of compost and its implication on crop yield under Sahelian conditions of Niger

Published online: 16 April 2016In Niger, farmers rely largely on organic resources such as manure and compost to address soil fertility problems and improve crop production. Ironically, they do not improve the fertilizer value of these organic resources or take into account their decomposition and nutrient release patterns before the application. This study aimed to assess the decomposition and nutrient release patterns of composted manure under field conditions and its implication on millet and cowpea grain yield. Litterbags arranged in randomized complete block design (RCBD) with three replications were used to assess decomposition and nutrient release of the compost. For the effect of composted manure and mineral fertilizer on millet and cowpea grain yield, two types of soil amendments were used; three levels of compost and four levels of mineral fertilizer. A 3 × 4 factorial experiment arranged in RCBD with three replications was used. After 84 days of decomposition, 40.3 and 56.5 % of compost mass losses were recorded respectively in 2013 and 2014. In 2013, 31, 74 and 97 % of N, P and K, respectively were released at 63 days of decomposition. Furthermore, in 2014, N, P and K release values of 58, 60 and 99 % were obtained at 84 days of decomposition. Combined application of 2500 kg ha−1 compost + 175/100 kg ha−1 NPK significantly (P < 0.001) recorded the highest millet yields of 1762 and 866 kg ha−1 while the highest cowpea yields of 360.5 and 389 kg ha−1 resulted from the application of 2500/5000 kg ha−1 compost + 75 kg ha−1 DAP. These findings suggest that, compost resulting from cattle manure plus cowpea haulm can be used by smallholder farmers to address soil fertility decline, improve nutrient availability and raise pearl millet and cowpea grain yield under strip cropping system