Southern Guinea Savanna Research Articles

IMPACT OF NITROGEN SOURCES ON THE PERFOMANCE OF LOWLAND RAINFED RICE AT EDOZHIGI IN THE SOUTHERN GUINEA SAVANNA OF NIGERIA

Field trials were conducted at Edozhigi, in the southern Guinea savanna of Nigeria during the 2020 and 2021 cropping seasons to determine the response of lowland rainfed rice to two Nitrogen sources (urea super granule (USG) and granular urea (GU)). There treatments consisted of five levels of USG (80, 90, 100, 110, 120 kg N ha-1) and six levels of GU (40, 80, 90, 100, 110, 120 kg N ha-1) and a control (0). The 12 treatments were laid out in a randomised complete block (RCBD) with three replicates. Result of the physical and chemical analysis of soil of the experimental field revealed that, soil had sandy clay loam texture with slightly acidic soil reaction. The soil organic carbon, total N, available P, exchangeable cataionic nutrients were all low in the soil which make the soil to have low fertility. Result of the study indicated that, plant growth and maturity period were not significantly affected by the application of N. The result further shows a significant response to application of USG, but not to GU. The highest paddy yield of 4.53 Mg ha-1 was recorded for USG at 90 kg N ha-1 which was significantly higher than that of the control and the GU treatments, but statistically similar to most of the other USG treatments. The USG is recommended as a source of N for the enhancement of the paddy yield.

The effect of organic and inorganic fertilizers on the production of maize in Minna, southern guinea savanna zone of Nigeria

The effect of organic and inorganic fertilizers on the production of maize in Minna, southern guinea savanna zone of Nigeria

Evaluating the Response of Watermelon (Citrullus lanatus (L.) to Organic and Inorganic Fertilization in Makurdi, Southern Guinea Savannah, Nigeria

Watermelon consumption in Nigeria is on the increase due to increasing awareness of its nutritional value while its production is on the decrease due to inefficiency of resource management (inputs like fertilizers). This study aims to optimize watermelon (Citrullus lanatus L.) production through the use of organic and inorganic fertilizers. The field experiment was conducted at the Teaching and Research Farm of Joseph Sarwuan Tarka University, Makurdi in the 2019 cropping season under rain-fed conditions. The site falls within the Latitude 7°4'1N and Longitude 8°3'7E at an elevation of about 97m above sea level in the Southern Guinea Savanna Agro-ecological Zone of Nigeria. The experiment treatments, namely and they were T1 (Control 0kg/ha), T2 (150 kg/ha Compost), T3 (200 kg/ha Compost), T4 (250 kg/ha Compost) and T5 (300 kg/ha NPK 20:10:10) laid out in Randomized Complete Block Design with three replications. The study revealed that in comparison with control treatments, 300 kg/ha NPK 20:10:10 produced (31.04t/ha) fruit yield, the application of 250 kg/ha compost enhanced growth and yield parameters of watermelon with fruit yield of (17.65t/ha). The research findings suggest that using compost manure at the rate of 250 kg/ha for watermelon production is viable since it is economical and environmentally friendly alternative to NPK fertilizer due to it cheap and easy to prepare methods, its beneficial effects on soil, groundwater and the environment. It is further recommended that, in Makurdi, smallholder farmers, should adopt the application of compost at the rate of 250 kg/ha for optimum yield

EFFECTS OF INTEGRATED NUTRIENT AND WEED MANAGEMENT ON WEED DYNAMICS AND MAIZE PERFORMANCE IN MINNA, SOUTHERN GUINEA SAVANNA OF NIGERIA

EFFECTS OF INTEGRATED NUTRIENT AND WEED MANAGEMENT ON WEED DYNAMICS AND MAIZE PERFORMANCE IN MINNA, SOUTHERN GUINEA SAVANNA OF NIGERIA

Yield Performance and Stability of Some Indian Castor Hybrids in Nigerian Ecology

Castor (Ricinus communis L.) is an industrial oil crop that is widely recognized as an ideal crop for tropical and subtropical regions. Nigeria has been identified as a country with high potential to meet her national castor oil need and provide surplus for export. This potential can be harnessed, only if adequate production technologies, such as improved varieties, are available to the farmers. In this research, three FTB castor hybrids (Code 11, Code 22 & Code 33) and two local checks (NCRICAS1 & NCRICAS1) were assessed for their yield performance and stability in Nigeria. The castor genotypes were evaluated in a replicated plots across six locations in the Southern and Northern Guinea savanna ecologies of Nigeria. The results revealed significant differences for traits assessed among the genotypes. Average seed yield among the hybrids ranged between 596.58kg/ha and 1372.49kg/ha. Average seed yields of the checks ranged between 849.58kg/ha and 1239.63kg/ha. The hybrid Code 33 out yielded the two local checks at four locations (i.e Badeggi, Benue, Kebbi & Sokoto) out of the six locations. The check 1 (Acc.036) recorded significant higher yield (1705.28kg/ha & 1648.15kg/ha) than the hybrid Code 33 (1573.91kg/ha & 867.58kg/ha) at Bacita and Bauchi locations. Besides recording comparable seed yield to the best hybrid (Code 33), the local check 1 (Acc.036) matured earlier than the hybrids evaluated. The GGE biplot view revealed good stability and responsiveness for both hybrid Code 33 (G5) and Acc.036 (G2). Based on performance per se, the hybrid Code 33 showed better adaptation to the ecology. However, further assessment on oil quantity and quality, and cost benefit analysis of the hybrid(s) in comparison to the local varieties is highly recommended.

Nodulation and Yields of Soybean (Glycine max L. Merrill) Varieties at Varying Phosphorus Fertilizer Rates in Lafia, Nigeria

Soybean production in Lafia, southern Guinea savanna zone of Nigeria, is impacted by soil phosphorus deficiency, affecting nodulation, nitrogen fixation, and overall crop productivity. Field experiments were conducted in 2018 and 2019 cropping seasons with different phosphorus fertilizer rates (0, 13, 26 & 39 Kg P2O5 ha-1) and six improved soybean varieties (TGX 1985-10F, TGX 1987-10F, TGX 1448-2E, TGX 1987-62F, TGX 1989-19F & TGX 1835-10E) to determine the effects of phosphorus fertilizer rates on nodulation and yields of soybean varieties. The results showed significant variation in soybean nodulation and yields when different phosphorus fertilizer rates were used. Among the six improved soybean varieties tested, TGX 1989-19F and TGX 1987-62F varieties performed best with 39 kg P2O5 ha-1. The results also show that plots that received a 39 kg P2O5 ha-1 produced the highest nodule number (26.3 & 28.7) and nodule weight (203.5 & 221.2 mg/plant) significantly in 2018 and 2019, respectively, compared to those with lower phosphorus rates. The effect of phosphorus fertilizer rates on soybean yields was apparent, with the 39 kg ha-1 phosphorus treatment yielding significantly higher yields than the lower phosphorus treatments. Notably, the TGX 1989-19F variety consistently outperformed the others, yielding the highest yield (1624.0 kg/ha). Based on the results, it is recommended that soybean farmers in the Lafia region consider increasing their phosphorus rates to 39 kg ha-1 for improved nodulation and subsequent yield gains. The TGX 1989-19F variety, due to its exceptional response to this phosphorus level, could be prioritized for cultivation to maximize returns. However, further research and on-farm trials must validate these findings across multiple growing seasons and farm management practices.

Morphometry of the Citrus Mealybug Planococcus citri (Risso) and its Feeding Impact on the Proximate Composition of Citrus Species Leaves in Makurdi Southern Guinea Savanna, Nigeria

The study assessed the feeding impact of citrus mealybug Planococcus citri (Risso) and its morphometry on (Citrus species L.) at the Teaching and Research Farm, Joseph Sarwuan Tarka University, Makurdi. A 2x5 factorial experiment comprising five species of two-year-old citrus seedlings (C. sinensis, C. nobilis, C. reticulata, C. limon, and C. aurantium) each replicated three times were planted on the field under screen cages in a Randomized Complete Block Design (RCBD). Fifteen stands were infested with 20 young adult female mealybugs each while 15 were un-infested to serve as the control. Data collected was analysed using GenStat Release 2007 (7.2) and means were separated by Duncan’s Multiple Range Test (DMRT) at P = 0.05. Results showed that the percentage of dry matter content was highest on the control compared with the infested plants. The proximate content of the host plant leaves indicated that all the control plants had more sugar than infested plants. Crude fibre and Ash content of infested host plants were lower than that of un-infested. The impact of mealybug feeding was most pronounced on C. sinensis and C. reticulata. Morphometrically, males of P. citri found on C. nobilis were in body length, width, and weight. Adult females, however, showed no significant variation in length and width across all citrus species. C. aurantium produced the heaviest females while C. reticulata had females with the lowest weight. In conclusion, C. nobilis is suitable for commercial production of seedlings. Routine inspection for early detection of mealybug infestation is recommended.

Effects of Conservation Tillage Method, Phosphorus Level, and Variety on Soil Organic Carbon and Cowpea Performance at Minna in Nigeria’s Southern Guinea Savanna

The study was carried out at the Teaching and Research Farm of the Federal University of Technology Minna, Gidan Kwano Campus in Latitude 9° 41' N, Longitude 6° 31' E, and Altitude 258.5 m above sea level. This study was conducted across 2 seasons within the cropping season of 2017 to determine the effects of tillage method, phosphorus level, and cowpea variety on soil organic carbon and cowpea performance in Minna. The experiment was therefore a 3x3x3 factorial arrangement in a split-plot design with tillage methods (zero, reduced, and manual ridging) and cowpea varieties (IT93K-452-1, IT99K-573-1-1, and IT90K-277-2) forming the main plot while phosphorus levels (0 P kg ha-1, 30 P kg ha-1, and 60 P kg ha-1) formed the sub-plot with 3 replicates. Results obtained revealed that soil organic carbon was not significantly affected by tillage method and phosphorus level alone, regardless of the planting season. Cowpea variety alone significantly affected organic carbon only in the late planting season. Zero tillage, 60 kg P ha-1, and IT93K-452-1 produced the highest soil organic carbon content, respectively. In the early season, N fixed was highest (0.98 g plant-1) when cowpea was fertilized with 60 Kg P ha-1 under zero tillage. The closest to this value (0.92 g plant-1) was recorded in the late season when 60 kg P ha-1 was supplied to cowpea under manual tillage. Regardless of the planting season and varietal difference, cowpea recorded the highest N fixed when fertilized with 60 kg P ha-1. Across varieties, cowpea fixed more N under zero tillage than the other tillage methods, especially in the early season. In the late season, only IT90K-277-2 fixed N (0.49 g plant-1) under zero tillage that was statistically not different from the highest N fixed due to manual tillage of soil under the cultivation of IT93K-452-1 and IT99K-573-1-1 (0.62 g plant-1, respectively). In the early season, IT99K-573-1-1 cultivated under zero tillage produced the highest grain yield (404.11 kg ha-1). Fodder yield followed a different trend compared to grain yield. In the early planting season, cowpea fertilized with 60 kg P ha-1 produced the highest fodder yield, while in the late season, the application of 30 kg P ha-1 produced the highest fodder yield. Regardless of the planting season, grain yield was highest when IT99K-573-1-1 was fertilized with 60 kg P ha-1. Averagely, soil organic carbon content, N fixed, and grain yield values were highest during the late planting than the early planting season. The reverse was, however, the case for fodder yield, seedling emergence, root length, root, and shoot biomass, respectively. For the best performance in cowpea production, farmers are encouraged to plant IT99K-573-1-1 on zero-tilled soil with phosphorus application at the rate of 60 kg ha-1. IT90K-277-2, which is the most genetically stable variety across seasons, will be most ideal in controlling negative climate change and should therefore be considered for further investigations.

Management of speargrass [<i>Imperata cylindrica (L.) Raeuschel</i>] in of southern agro-ecologies of Nigeria

Speargrass [Imperata cylindrica (L.) Raeuschel] infestation limits crop growth and yield. The effects of tillage methods, kenaf genotypes, and plant spacing patterns were studied for speargrass suppression at Eruwa (Derived Savanna) and Kishi (Southern Guinea Savanna) in 2015 and 2016. These were randomized in a Split-split plot design with three replicates. Agronomic data collected were analyzed, and the means were separated at P ≤ 0.05. Results showed that tillage enhanced weed control efficiency (10%), improved I. cylindrica suppression, and kenaf performance, relative to plant sown in no-till plots at both locations. The bast-fibre yield was higher in Ifeken DI 400 than in Ifeken 400 at Eruwa, but genotypes had similar bast-fibre yield at Kishi. Also, both genotypes had comparable I. cylindrica biomass and weed control efficiency at Kishi, while Ifeken 400 had higher weed control efficiency than Ifeken DI 400 at Eruwa, due to better suppression of I. cylindrica. The agronomic traits measured and weed control efficiency (WCE %) had a substantial inverse relationship with I. cylindrical growth at both locations. Tillage improved bast fibre yield (26 – 32%), core fibre yield (20 – 28%), and seed yield (26 – 59 %) relative to no-tilled plots. Ifeken 400 showed superior weed-suppressive traits and optimum fibre yield to Ifeken DI 400 at both locations. Tilling speargrass-infested land, with kenaf plant spacing of 50 cm × 10 cm and 50 cm × 15 cm with early canopy formation and better weed suppression are considered for an integratedspeargrass management scheme.

Effect of rhizobial inoculation on the nodulation, growth and yield of Soybean in the Savannah regions of Nigeria

Rhizobial inoculation is the introduction of rhizobium bacteria in a high concentration into the soil before or during the planting of crops. Field experiments were conducted during the rainy seasons of 2020, 2021, and 2022 at the Research farm of the Department of Crop Sciences, Faculty of Agriculture, University of Abuja, Gwagwalada, the Southern Guinea Savanna of Nigeria. The study aimed to analyse the effect of Bradyrhizobium japonicum inoculation on the nodulation, growth and yield parameters in Soybean. The treatments consisted of three Soybean varieties, namely TGX 1485-1D (early maturing), TGX 1448–2E (medium maturing), and TGX1987–10F (medium maturing) and Two levels of inoculant (control, with inoculant), The experiment was laid out in a randomized complete block design (RCBD), with three replicates and 54 plots. Agronomic and cultural practices were duly observed, and data were collected for growth and yield parameters. Data were subjected to analysis of variance (ANOVA) using the ‘agricolae’ package in the R Statistical Programme (R version 4.2.2.), T-test was conducted using the SPSS statistical package (Version 23), and the Duncan Multiple Range Test (DMRT) and Standard error (SE) were used to separate significant means at (P ≤ 0.05). Results showed that for all varieties of Soybean observed, the inoculated had the best performance (2685kg/ha, 2842.3kg/ha, 3038.5Kg/ha for TGX 1485-1D, TGX 1448–2E and TGX1987–10F respectively best compared to the control.

Effect of Lambda-cyhalothrin + Carbofuran Application and Habitat Modification on Population Dynamics Of 0rseolia oryzivora (Diptera: Cecidomyiidae) in Relation to its Parasitoids On Rice

ABSTRACT This experiment was carried out between 2018 and 2019 at the experimental site of National Cereals Research Institute’s identified hot spot (Edozhigi) for Africa rice gall midge (0rseolia oryzivora) infestation in Nigeria. Edozhigi in Niger State is within the southern Guinea savanna agro-ecological zone at latitude 09°45' N, longitude 06°07' E, to test integrated inluence of habitat manipulation, lambda-cyhalothrin and carbofuran on population dynamics of 0. oryzivora in relation to its parasitoids on rice. The treatments were arranged in split-plot and laid out in a RCBD with three replicates. Data were collected on number of tiller / stand, plant height, days to 50 percent flowering, percent incidence, percent severity, percentage parasitism of 0. oryzivora, panicle per meter square, grains per panicle and yield of rice. Data collected were subjected to Analysis of Variance and significant means were separated using Student Newman Keuls Test, (SNK) at 5 % probability. The result showed that Rice plots treated with P. scrubiculatum + 0.38L/ha lambda-cyhalotrin +3.75kg/ha carbofuran had lower incidence (2.36) and severity (1.54) of 0. oryzivora compared with incidence (7.99) and severity (7.40) respectively found in untreated plots (control). It also had significantly higher yield (3263.95kg/ha) compared with the yield (2688.28kg/ha) in control plots. In conclusion, having P. scrobiculatum at boarder of net plots enhanced number of parasitoids and reduced attack of rice by 0. oryzivora. Integration of habitat modification with insecticide application offers better protection of rice against O. oryzivora. Key words: Habitat P. scrobiculatum, Infestation, Modification, Galls.

Preliminary Evaluation of Onion Bulb and Tobacco Leaf Extracts for Insect Control and Yield of Cowpea in the Southern Guinea Savanna of Nigeria

The study evaluated the effects of onion (Allium cepa) bulb and tobacco (Nicotiana tabacum) leaf extract on the insect pests and yield components of cowpea. The extracts were tested on number of the flower thrips, Megalurothrips sjostedti Trybom, the pod-sucking bug, Clavigralla tomentosicollis Stal, the pod borer, Maruca vitrata (F.) and cowpea aphid, Aphis craccivora Koch. Also evaluated were the dry seed weight, 100-seed weight, pod length, number of pods per plant, number of seeds per pod, pod load, pod damage and pod evaluation index. Field experiment was conducted in the Faculty of Agriculture, University of Ilorin, Ilorin, Nigeria. Plots were laid out in a randomized complete block design with three replications. Treatments included 10% (w/v) of each of onion bulb and tobacco leaf extracts, synthetic insecticide (Cypermethrin 1 L/ha) and untreated control. Results revealed that cowpea treated with the plant extracts had significantly (p<0.05) lower insect pest population than plants in untreated plots which suffered greater insect pest attack. However, plots treated with Cypermethrin produced significantly higher number of seeds per pod than other treatments. Nevertheless, tobacco leaf extract produced significantly (p<0.05) heavier 100-seed weight than other treatments including the control. It could be concluded that the plant extracts had potential to replace the synthetic insecticide for control of insect pests of cowpea, thus ensuring environmental safety.

Evaluation of Sowing Methods and Herbicide Mixtures for Weed Management and Productivity in Sesame (Sesamum indicum L.)

Sesame is an oil seed crop with great economic value. However, the production of this crop has been limited by weed competition, which prompted a field experiment during the 2021 cropping season in two locations: Teaching and Research Farm, Kwara State University, Malete, and National Centre for Agricultural Mechanization (NCAM), Idofian, Ilorin, Kwara, Nigeria. The aim was to determine the treatment combinations of sowing methods and herbicide mixtures for the effective management of weeds and for increasing sesame productivity in the southern Guinea savanna of Nigeria. The experiment consisted of twenty treatments comprising two sowing methods (dibbling and drilling) and ten weed control methods. Results showed that all the weed control methods reduced weed dry matter (67.15–186.20 and 42.00–92.45 g/m2) than the weedy check (291.55 and 155.55 g/m2) at Malete and NCAM, respectively. They also reduced the weed density (48.40–68.45 and 34.00–50.00/m2) compared to the weedy check (103.60 and 73.15 g/m2) at Malete and NCAM, respectively, from 6 to 12 weeks after planting (WAP). Dibbling (85.15 and 48.81 m2) proved superior to the drilling method (172.42 and 51.58/m2) for the management of weeds from 6–12 WAP and for promoting higher crop yield (dibbling: 78.90 and 422.70 kg/ha; drilling: 37.50 and 326.80 kg/ha) in Malete and NCAM, respectively. The treatment combinations with the highest gross margin were hoeing twice at 3 and 6 WAP × dibbling ($ -191.15 and $ 318.57), pendimethalin (P) + diuron (D) at 0.5 + 0.5 kg a.i./ha ($ -199.88 and $ 182.43), 2.0 + 1.5 × dibbling ($ -273.59 and $ 156.65) and butachlor (B) + diuron (D) at 1.5 + 1.0 kg a.i./ha × drilling ($ -269.59 and $ 177.38) at Malete and NCAM, respectively. Therefore, it is recommended that the dibbling sowing method at a spacing of 30 cm × 30 cm and thinned to 3 plants/stand integrated with herbicide mixtures of pendimethalin at 0.5 + 0.5 kg a.i./ha is recommended as an alternative to hoe weeding for effective weed control, higher yield of sesame, and economic returns.

Assessment of Weathering Intensity and Pedogenesis of Lithosequence Located in Two Agroecological Zones of Nigeria

Elemental oxides can help to identify processes of soil formation and the degree of soil development. This study assessed soil development and weathering intensity in soils developed on schist and older granite in upland tropical rain forest and southern guinea savanna agro ecological zones of Nigeria. Soil profile samples were collected in each of the study locations. In the laboratory, total elemental oxides was determined using the energy dispersing X-ray Fluorescence (EDXRF) XRF SPEC (Minipal 4). The relative intensity of weathering of total elemental oxides was determined by choosing titanium as the suitable indexing element and the relative gain or loss of element was estimated using relative retained element (Ro) equation. Result obtained, revealed that SiO2 was the most abundant in the soils. Distribution of Al2O3 and CaO showed the direction of the pedogenic age. Older granite soil had higher values of Al2O3 and lower values of CaO. There was negative relationship of SiO2 with Al2O3 and Fe2O3. The trace elemental oxides were less than 1% and zirconium oxide was the most retained oxide in the soils. Soil which developed on schist retained more of the trace elements than soil on older granite. There was evidence of alitization, ferritization and desillication in the soils. Parent materials contributed to loss and gain of trace elemental oxides. Older granite soil was more weathered and pedologically older than schist derived soils.

Assessment of Soil Quality Conditions for the Cultivation of Upland Rice in Bwari Area Council, Abuja Nigeria

1 2., 3 & 4 Department of Geography and Natural Resource Management University of Uyo Uyo, Akwa Ibom State, Nigeria Phones: 1+234802-303-3114, 2+234803-781-0411; 4+234803-104-9807 Email: 1meansa1@yahoo.com; 2uwemituen@gmail.com; 4udyudofia07@gmail.com ABSTRACT This study examined the suitability of the soil chemical properties in selected communities of Bwari Area Council, FCT, Nigeria for the cultivation of upland rice. The communities which include Igu, Gyeyidna, Kuchiko, Piawe, Dutse, Jikoko, Shere, Piko, Ushafa and Jigo, were selected as non-contiguous pair from five geographical wards (Igu, kuduru, Dutse, Shere and Ushafa) in the Area Council. They were purposively selected using the criteria of 500 metres and above elevation (upland condition) and agricultural preponderance. The soil samples were collected from farmland in each of the communities using systematic sampling techniques, which involved measuring out a 100 by 100 metres quadrat and dividing it into sixteen equal grid squares with a dimension of 25 by 25 metres. Soil samples were taken at the mid points of each grid square at a depth of 0 – 30cm. The sixteen soil samples for each quadrat were uniformly mixed into one bulk composite sample for each community. The soil results were compared with the standard land quality requirements for upland rice cultivation for Southern Guinea Savanna. To the first study objective, pH, organic carbon, total nitrogen, available phosphorus, calcium, magnesium, potassium, and cation exchange capacity (CEC) were assessed. Results show that there was no significant difference between the soil quality of the study area and standard soil quality requirements for the cultivation of upland rice. Based on these, it was concluded that the chemical soil properties of the sampled communities in Bwari Area Council will support the cultivation of upland rice, even though there are spatial variation in the soil chemical properties of the study area. Some strategic recommendation were made such as: the need to reduce the soil pH of the study area from its fairly alkaline state to moderately acidic level suitable for upland rice cultivation in Bwari Area Council. Keywords: Soil, Quality, Condition, Upland, Rice, Cultivation, Bwari Area Council, Abuja, Nigeria Aims Research Journal Reference Format: 1Ansa, Iniubong E. 2Ituen, Uwem J., 3Igomah, Maxwell M. & 4Udofia, Uduak-Obong O. (2023): Additive Manufacturing: A Paradigm Shift For Industrialization In Africa . Advances in Multidisciplinary and Scientific Research. Vol. 9. No. 2, Pp 1–16. www.isteams.net/aimsjournal. dx.doi.org/10.22624/AIMS/V9N2P1

Integrating traditional knowledge with modern breeding techniques: A case study of cattle production in Nigeria's southern guinea and derived savanna agroecological zones

Nomadic pastoralists and agropastoralists are the primary custodians of cattle production in Nigeria, they operate a low external input production system which is proving difficult to modernize especially in the areas of breeding and reproduction for genetic improvement. This study was carried out to gather historical, phenotypic, and perceived genetic information associated with cattle breeding and reproduction practices of the nomadic pastoralists and agropastoralists in the Nigeria Southern Guinea Savanna and Derived Savanna agroecological zones through interviewer-led focus group meetings. The study revealed that the respondents operate similar breeding practices which are native knowledge and practices preserved and transmitted over many generations. The practices are communal in nature and consider climate conditions as well as being comparably similar with the modern scientific standards, hence it was concluded that the respondents have the potential to easily adopt the modern approach of animal breeding and reproduction. These findings suggest a pathway for integrating traditional knowledge with contemporary breeding techniques to enhance cattle production. Future research should explore specific strategies to facilitate this integration and evaluate its impact on productivity and sustainability in the agro-ecological zones

Agroecological zones influence maize infestation and damage severity by the fall armyworm (Spodoptera frugiperda [J. E. Smith, 1797]) in southwestern Nigeria

The fall armyworm (Spodoptera frugiperda) is an invasive and highly destructive insect pest that has caused extensive damage to maize in Africa since its first report on the continent in 2016. Information on fall armyworm infestation and damage within African agroecologies is essential for the development of appropriate pest management strategies, but these are scant in Nigeria. Consequently, in this study, fall armyworm infestation levels and severity of damage to maize in the three major maize-growing agro-ecological zones (humid forest, derived savanna, and southern guinea savanna) of southwestern Nigeria was investigated using standard field sampling protocols. Results showed that maize infestation and damage severity varied across agroecological zones, with the humid forest being the most impacted. Information provided will enhance decision-making for effective management of the fall armyworm in southwestern Nigeria.

Exploring the potential of mapped soil properties, rhizobium inoculation, and phosphorus supplementation for predicting soybean yield in the savanna areas of Nigeria.

Rapid and accurate soybean yield prediction at an on-farm scale is important for ensuring sustainable yield increases and contributing to food security maintenance in Nigeria. We used multiple approaches to assess the benefits of rhizobium (Rh) inoculation and phosphorus (P) fertilization on soybean yield increase and profitability from large-scale conducted trials in the savanna areas of Nigeria [i.e., the Sudan Savanna (SS), Northern Guinea Savanna (NGS), and Southern Guinea Savanna (SGS)]. Soybean yield results from the established trials managed by farmers with four treatments (i.e., the control without inoculation and P fertilizer, Rh inoculation, P fertilizer, and Rh + P combination treatments) were predicted using mapped soil properties and weather variables in ensemble machine-learning techniques, specifically the conditional inference regression random forest (RF) model. Using the IMPACT model, scenario analyses were employed to simulate long-term adoption impacts on national soybean trade and currency. Our study found that yields of the Rh + P combination were consistently higher than the control in the three agroecological zones. Average yield increases were 128%, 111%, and 162% higher in the Rh + P combination compared to the control treatment in the SS, NGS, and SGS agroecological zones, respectively. The NGS agroecological zone showed a higher yield than SS and SGS. The highest training coefficient of determination (R2 = 0.75) for yield prediction was from the NGS dataset, and the lowest coefficient (R2 = 0.46) was from the SS samples. The results from the IMPACT model showed a reduction of 10% and 22% for the low (35% adoption scenario) and high (75% adoption scenario) soybean imports from 2029 in Nigeria, respectively. A significant reduction in soybean imports is feasible if the Rh + P inputs are large-scaled implemented at the on-farm field and massively adopted by farmers in Nigeria.

Soil properties affecting soil organic carbon stock of different land use types in two agro-ecological zones of Nigeria

Soil organic carbon (SOC) stock is the carbon proportion that is of biological origin stored with respect to soil depth. It is more prone to loss than soil inorganic carbon. High sequestration of SOC in soil is germane to the improvement of soil quality and mitigating impact of climate change. Thus, this study was carried out to evaluate soil properties affecting SOC stock in the two agro-ecological zones, namely Upland Rainforest (Ado-Ekiti) and southern Guinea Savanna (Kabba) agro-ecological zones of Nigeria, with respect to three selected land use types; arable, oil palm and wetland. Random collection of soil samples was carried out at four varying depths (0-15, 15-30, 30-45, and 45-60 cm) for evaluation of soil properties. The SOC stock regression models for the two agro-ecological zones showed that land use, SOC, pH, SOM (soil organic matter), Ex-K, Ex-Ca, Ex-Mg (exchangeable potassium, calcium, magnesium, respectively), BD (bulk density), and gravel content would predict variation in SOC stock in the two agro-ecological zones with coefficient of determination (R2) values of 0.952 and 0.996 for Kabba and Ado-Ekiti respectively. Principal component analysis identified that in the soil of the southern Guinea Savanna agro-ecological zone, SOC, CEC, EA, Ex-Na, land use, clay content, and soil depth with Eigenvalues > 1 explained 80.58% of sample variance while in the soil of the Upland Rainforest agro-ecological zone, Ex-Ca, SOC, Ex-Na, EA, sand and silt contents with Eigenvalues > 1 explained 78.81% of sample variance as potential determinants of SOC stock.

Establishing Optimal Planting Windows for Contrasting Sorghum Cultivars across Diverse Agro-Ecologies of North-Eastern Nigeria: A Modelling Approach

In the context of climate change, the sowing date and cultivar choice can influence the productivity of sorghum, especially where production is constrained by low soil fertility and early terminal drought across the challenging agro-ecologies of north-eastern Nigeria. Planting within an optimal sowing window to fit the cultivar’s maturity length is critical for maximizing/increasing the crop yield following the appropriate climate-smart management practices. In this study, the APSIM crop model was calibrated and validated to simulate the growth and yield of sorghum cultivars with differing maturing periods sown within varying planting time windows under improved agricultural practices. The model was run to simulate long-term crop performance from 1985 to 2010 to determine the optimal planting windows (PWs) and most suitable cultivars across different agro-ecological zones (AEZs). The performance of the model, validated with the observed farm-level grain yield, was satisfactory across all planting dates and cropping systems. The model predicted a lower mean bias error (MBE), either positive or negative, under the sole cropping system in the July sowing month compared to in the June and August sowing months. The seasonal climate simulations across sites and AEZs suggested increased yields when using adapted sorghum cultivars based on the average grain yield threshold of ≥1500 kgha−1 against the national average of 1160 kgha−1. In the Sudan Savanna (SS), the predicted optimum PWs ranged from 25 May to 30 June for CSR01 and Samsorg-44, while the PWs could be extended to 10 July for ICSV400 and Improved Deko. In the Northern Guinea Savanna (NGS) and Southern Guinea Savanna (SGS), the optimal PWs ranged from 25 May to 10 July for all cultivars except for SK5912, for which predicted optimal PWs ranged from 25 May to 30 June. In the NGS zone, all cultivars were found to be suitable for cultivation with exception of SK5912. Meanwhile, in the SGS zone, the simulated yield below the threshold (1500 kgha−1) could be explained by the sandy soil and the very low soil fertility observed there. It was concluded that farm decisions to plant within the predicted optimal PWs alongside the use of adapted sorghum cultivars would serve as key adaptation strategies for increasing the sorghum productivity in the three AEZs.