Prospects for Intensifying Soil Fertility Management on the Growth and Yield of Assava in Ghana

Crop-specific fertilizer recommendations are necessary to improve yield and enhance food security in Ghana. This approach would help in improving crop productivity while maintaining a good soil health status. A new NPK fertilizer has been recently developed by the private sector with Nitrogen (N), Phosphorus (P), and Potassium (K) proportions of 11:22:21 respectively for improved cassava root yield. This study evaluated the right and economic rate of this fertilizer to apply for improved cassava productivity and farmer livelihoods. Rates of 0, 300, 400, 600, and 800 kg/ha of newly developed fertilizer were applied at Fumesua and Akumadan located in the forest agro-ecological zone, and at Ejura and Techiman located in the transitional agro-ecological zone of Ghana. The experiments were conducted in two growing seasons (May 2019 to April 2020 and May 2020 to April 2021). Increases in cassava growth were observed with the increasing levels of fertilizer at all locations and in the two growing seasons. Cassava yield was in the linear phase of the fertilizer response curve. It ranged from 28 to 52 tons/ha with the increasing fertilizer levels. Cassava in the forest agro-ecology had better growth and 25% more yield than other locations. Fertilizer rates between 0 and 400 were found to have the best yield returns and sufficient profit opportunities to sensitize adoption by financially constrained farmers. The results indicate that the newly developed fertilizer (11:22:21 N:P2O5:K2O) can improve cassava productivity in the inherently poor soils of Ghana. Keywords: fertilizer recommendation; plant nutrients; rainfall; agronomic practices; cassava productivity; root yield DOI: 10.7176/JBAH/12-18-03 Publication date:September 30th 202

Combining deficit irrigation and nutrient amendment enhances the water productivity of tomato (Solanum lycopersicum L.) in the tropics

Water availability for irrigation farming is one of the greatest challenges associated with the increasing spatio-temporal effects of climate change and variability on tomato production, especially in tropical regions. This study was conducted to demonstrate the combined effect of irrigation and nutrient management as a water-saving strategy to maximize nutrient and water productivity in tomato production. The research was conducted in a screen house at the CSIR-Crops Research Institute (CSIR-CRI), Kumasi, Ghana using the split-plot design in the 2020 and 2021 cropping seasons. The main plot consisted of a single full irrigation at 100% recommended crop water requirement and two deficit irrigation levels (75 and 50% of the crop water requirement). The subplots consisted of two nutrient amendments (inorganic fertilizer and organic compost) and a control (without any nutrient amendment). Data from the research was used to parameterize the DSSAT CCROPGRO model to simulate the interactive effect of irrigation and nutrient management on the yield of tomatoes. Plant height and stem girth did not have a specific influence on tomato yield, but the number of branches had a positive effect on tomato yield. The combined use of inorganic fertilizer and full irrigation was found to improve tomato yield up to 7691.4 and 9009.9 kg/ha whereas treatment with no fertilizer application at 50% deficit irrigation recorded the lowest tomato yield of 1423.9 and 1739.2 kg/ha in 2020 and 2021, respectively. For the two deficit irrigations (50 and 75% ETc), organic compost produced the highest tomato yield. Deficit irrigation recorded higher crop water productivity (CWP) compared to full irrigation. At 50% deficit irrigation, organic compost recorded the highest CWP of 4.54 kg/m3 in 2020 while inorganic fertilizer recorded the highest CWP of 5.52 kg/m3 in 2021. No fertilizer at full irrigation recorded the lowest CWP of 1.37 and 1.67 kg/m3 in 2020 and 2021, respectively. This study has revealed that deficit irrigation with organic compost has the same effect on yield and water productivity as full irrigation with inorganic fertilizer. The strong agreement observed between the measured and simulated yields under the different irrigation and nutrient management shows that the DSSAT CROPGRO tomato model can be used to simulate tomato fruit yield under future climate scenarios. However, the general overestimation of the measured tomato yield shows the limitations of the model to simulate the real-world complexity of cropping systems under controlled conditions. This calls for more research into crop system modeling in controlled environment agriculture

Training Manual on Bundled Climate Smart Agriculture, Climate Information Services and One-Health Technologies for Priority Value Chains

The manual is an addendum to the prioritized and bundled Climate Smart Agriculture (CSA) and Climate Information Services Innovations that is One Health Sensitive. The manual is designed as an extension and training tool for trainers of trainees (TOT) and extension agents to support smallholder farmers most especially stakeholders in AICCRA intervention communities. Users will find the manual very useful and it is hoped that Agriculture Extension Agents (AEAs), farmers, students, and other end users will apply the modules to increase crop production in the target agroecologies. Specifically, the manual provides climate information services, climate smart agriculture innovations and one health intervention that have been prioritized along maize, cowpea, yam, sweetpotato and tomato value chains

Improving Soil Fertility with Organic Fertilizers

Organic fertilizers with low C:N ratios can be applied to supply both macro and micronutrients to the soil. Aside nutrient supply, they can improve soil structure, texture, water holding capacity and nutrient holding capacity. The mechanisms that may interplay to allow organic fertilizers to affect the soil and crop yields may include improved nutrient synchrony, general improvement in fertility and/or priming effects. The rate, timing and method of organic fertilizer application must be considered to reduce N and P losses during organic fertilizer application. To meet the nutrient requirement of crops, organic fertilizers must be applied in large quantities, so it is more prudent to apply locally available resources. In a case study where sole organic fertilizer, sole inorganic fertilizer and their combinations were applied under rain-fed conditions, it was observed that manure had the potential to hold nutrients longer. This is a positive finding for drought prone areas

Optimizing Slow-Release Fertilizer Rate for Crop and Soil Productivity in Kimchi Cabbage Cropping Systems in the Highlands of Gangwon Province

Slow-release fertilizer (SRF) improves Kimchi cabbage (KC) productivity in the Highlands of Gangwon Province in South Korea; however, optimum rates for the region are not established. This study investigated the optimum and most economical rate of SRF that maximizes KC yield, nutrient uptake and nitrogen use efficiency (NUE) and enhances soil quality in two experiments at the Highland Agriculture Research Institute. Post-harvest soil N (mg kg−1), P2O5 (mg kg−1), K, Ca and Mg (cmolc kg−1), pH (1:5), electrical conductivity (EC; dSm−1) and organic matter (OM; g kg−1) were measured to assess soil quality. Added net returns (ANR) of treatments were evaluated. Recommended N rate (238 kg ha−1) for KC production was the basis for treatment applications. Treatments included no fertilizer control (‘nf’), full N recommendation SRF (SF1), ½ N recommendation SRF (SF0.5), double N recommendation SRF (SF2) and full N recommendation conventional fast fertilizer (FF). Results showed that SF0.5, SF1 and SF2 influenced the highest KC marketable yield in both experiments (66–74 and 42–66 Mg ha−1, respectively). SRF rates between 0.5 and 1 times the N recommendation produced the highest possible linear increases in marketable yield; and the most economical, with ANR > KRW 83 million ha−1 in the first experiment and > KRW 22 million ha−1 in the second. Crop N, P, K, Ca and Mg uptakes were highest among the three SRF rates in both experiments. SF0.5 influenced the highest (91%) NUE in the first experiment; however, it left 8 mg kg−1 N by the end of this experiment compared to the start-up 27.2 mg kg−1 N. Thus, nutrient mining occurred. Soil N increased between 23 and 135 mg kg−1 by SF 1 and 2 in both experiments. Soil EC spiked to 0.6 dSm−1 from the initial level of 0.2 dSm−1 by SF2 in the first experiment. Soil pH, P2O5, K, Ca and Mg levels post-harvest were comparable among treatments in both experiments. SF0.5, 1 and 2 increased soil OM by 7–16% above pre-experimental levels in the second experiment. In conclusion, SRF rates between 0.5 and 1 for KC produced the maximum corresponding KC yield and were the most economical. SRF rates ≤ 0.5 pose risks of nutrient mining, which could jeopardise native soil fertility. SF1 and 2 improved some soil quality indices (N and OM). However, SF2 potentiates risks of soil salinity and large P losses, and it is less economical. Therefore, for holistic sustainability of the cropping system, the optimum SRF rate should lie between 0.5 and 1 N recommendation

Validating Climate Smart Agriculture and One Health Technologies for Improved Climate Resilience and Productivity Throught Piloting

Building community resilience to climate risk through demonstration plots is a priority in sub-Saharan Africa, where the agricultural system is mainly rainfed and underdeveloped due to multiple underlying causes, such as limited access to information, improved seeds/inputs, modern production practices, and technologies. The use of demonstration plots serve as a platform to promote validated climate-smart and One health technologies.. Under the current project, demonstration plots were used to provide training on good production practices of the various AICCRA-Ghana value chains. Thirty-one (31) demonstration plots were established across eighteen (18) communities in four agroecologies (Coastal savannah, Transition, Guniea savannah, and Sudan savannah) of Ghana. The value chains piloted were maize (13 pilots), yam (6 pilots), cowpea (8 pilots), and sweet potato (4 pilots). These value chains were chosen because of their socio-economic importance in Ghana. Maize and cowpea technologies constituted 42 and 26% of the number of demonstration plots established, respectively. Twenty-one field days were organized to introduce beneficiaries and other stakeholders in the project intervention communities to the various technologies the project demonstrated (i.e climate-smart seeds, One health innovations, and good agronomic practices). A total of One thousand one hundred and thirteen (1113) people were reached out to and directly participated in the field days. Four hundred and fifty-nine of the participants, representing 41% were female. While farmers from intervention communities expressed gratituted to the project, farmers from other communities that participated in the field days have requested for the project to extend such demonstrations to them. Generally, participants expressed their satisfaction and willingness to adopt these new technologies and incorporate them into their farming business next year and beyond