Asian Journal of Soil Science and Plant Nutrition

Sorghum is one of the most important cereal crops in Ethiopia which is grown most dominantly in the low land area where drought predominates. In this area farmer’s preference to improved sorghum variety is dependent on earliness and drought tolerance traits. The objective of the study was to evaluate the genetic diversity of early maturing sorghum genotypes for drought tolerance by using principal component and cluster analysis. Twenty three early maturing sorghum genotypes were phenotyped under post-flowering moisture stressed and non-stressed environment using RCBD design in adjacent experiment. The analysis of variance revealed significant variation among genotypes for most of the traits for both moisture environments. Post-flowering drought reduce the value for all of the traits except flag leaf area and average grain yield was reduced by 21%. Five genetically divergent clusters which showed significant inter cluster distance were observed in both environments. Genotypes in cluster one showed best performance for grain yield and yield components under non-stress environment. Under stressed environment, genotypes under C1, and C2 revealed best performance for drought tolerance and yield traits, respectively. Therefore, the performance of genotypes under these clusters and different clustering pattern observed depicts the divergence of genotypes for drought response which creates opportunity for further improvement through selection and hybridization. Principal component analysis revealed five and seven PC captured 80% and 87% of total variation observed under stressed and non-stressed environment, respectively.

The interaction of land use and time on some soil water transmission properties and fertility status of an Ultisol was examined. Results indicate that the texture of the soils ranged from sandy loamy to sandy clay loam and was unaffected by land use and time. The bulk density varied significantly across the land uses with the Sand mining site SM having the highest bulk density of 1.7 and 1.78 g/cm³ in the first and second years respectively. The Primary forest, PFL had the lowest BD of 1.50 and 1.78 g/cm³ in the first and second year of studies respectively. Similarly the percentage porosity varied significantly across the four land uses and has its highest value of 43.1 and 42.3% in the first PFL of the first and second year studies. Also the saturated hydraulic conductivity KSat and moisture content MC were significantly different across the four land uses, the Ksat was highest in the PFL in both first and second year of studies (17.2 and 14.7 cm/min), the least Ksat values of 6.70 and 5.88 cm/min occurred in the 1^st year sand mining site SM. Similarly there was a significant difference (P>0.05) in the percentage organic matter OM, Total nitrogen N, available phosphorous P, exchangeable acidity, Percentage base saturation BS, and CEC across the land uses, however the total N was only significant in land uses PFL and not in the other land uses. Generally the soil quality indicators ranged from low to moderate in ratings and have affected productivity of recent in the area. Appropriate land uses that will restore the productive potentials of the soil should be adopted and sustained. Similarly the organic matter of the soils should be improved on as this will go a long way in improving appreciably the poor soil water transmission properties.

Aims: To introduce brachiaria grasses in Meru and Embu Counties to increase the range of fodder/forage varieties available to smallholders through the use of climate-smart brachiaria grasses for increased income. The project also aimed at identifying the best brachiaria varieties suitable for the target Agro-Ecological ones through evaluation by the farmers and yield assessment.

Study Design:  Randomized Complete Block Design (RCBD)

Place and Duration of Study: The study was carried out in Embu and Meru Counties during the short rains of 2015.

Methodology: Three varieties of brachiaria were introduced in the short rains of 2015 in KALRO Embu, Geeto Igoji in Meru, and Embu County. These were Brachiaria decumbense -Cultivar Basilisk, Brachiaria brizantha- Cultivar BRS Piata and Brachiaria brizantha- Cultivar Toledo. Plots of 5x5m were planted and replicated three times using Randomized Complete Block Design (RCBD) to increase the range of fodder/forage varieties available to smallholder and assess the yield and acceptability of the different brachiaria grasses varieties. The three varieties were planted in the mega demonstration sites. The grass performance was analyzed through pairwise ranking and the grass with the best attributes was selected. Yield data was also collected.

Results: After ranking, the results indicated that the rate of growth and the amount of biomass as the most important attributes followed by the animals' response after feeding and the rate of rejuvenation after harvesting respectively. Using the attributes, the group members concluded that Brachiaria decumbense- Cultivar basilisk was the best followed by brachiaria brizantha- Cultivar piata and finally brachiaria brizantha- Cultivar Toledo.

Conclusion: In conclusion, based on the attributes, the best brachiaria varieties for use in Embu and Meru Countries are Brachiaria decumbense –Cultivar Basilisk and Brachiaria brizantha- Cultivar Toledo. Based on yield, Brachiaria brizantha- Cultivar Toledo is the best in Embu County while Brachiaria brizantha- Cultivar Basilisk is the best in Meru County.

The evaluation of the effects of the digestate produced by the reactor EB.06019.LHT-MWINDA on the pH of Kimwenza soil and the growth of Amaranthus cruentus was conducted during the dry season (June-July 2019). Two treatments were used for the experiment: NPK (T1) and digestate (T2). The untreated soil was taken as a negative control(T0). The results obtained show that the digestate has a more neutralizing effect on the acidity of the Kimwenza-mission soil than the mineral fertilizer: the pH increased from 4.40 ± 0.33 to 9.28 ± 0.45 for T2 versus 5.19 ± 0.59 to 7.71 ± 0.29 for T1. The plants treated with T2 gave leaves with relatively more weight (1.8 ± 0.5g) than those obtained with T1 (1.06 ± 0.87g). It was observed that plants treated with digestate were taller (10,4 ±1,1m) than those with NPK (9,45 ±1,13m). The average number of leaves obtained from plants was 7.06 ; 6.36 and 5.97 respectively for T2, T1 and T0. These results are an indication that the digestate produced by the reactor EB.06019.LHT-MWINDA could be used for the amendment of the acidic soil of Kimwenza-Mission and therefore contribute to reducing significantly the use of synthetic agro-chemicals, hence decreasing residual environmental and human health hazards.

Quantification of pesticide residues in retail samples of food is one way to determine the level of human exposure to these chemicals and hence their potential health hazards. The study was aimed at quantifying the level of some known pesticides in retail samples of Vigna unguiculata (L.) Walp. (Cowpea) from two cropping seasons. Five cultivars of cowpea from two different harvest seasons (2016/2017 and 2017/2018) were purchased from Ogige Market, Nsukka, Enugu State, Nigeria. The cowpeas were identified based on city/state where they were cultivated. Two foreign samples were also purchased from London, UK. The pesticide residues were determined using gas chromatography coupled with electron capturing detector (GC-ECD). The results showed that the retail samples of cowpea contained residues of one or more organochlorines and organophosphates. The levels of post-harvest pesticides, 2, 2-dichlorovinyl dimethyl phosphate (DDVP) in 2016/17 season (0.02 μg/g) exceeded the international permissible standards (0.01 μg/g). The levels of the pre-harvest pesticides, glyphosate was low in both seasons (0.01 μg/g) when compared to the international permissible standards (0.1 μg/g).  The DDVP was not detected in the two foreign samples. HCB (Hexachlorobenzene), α-HCH (alpha-Hexachlorocyclohexane), Chlorpyrifos, g-chlordane, t-nonachlor, p-p’-DDT (Dichlorodiphenyltrichloroethane), p-p’-DDE (Dichlorodiphenyldichlo-rowthylene), and p-p’-DDD (Dichlorodiphenyldichloroethane) were detected in the cowpea from two cropping seasons despite being banned from agricultural use. This could be due to the additional application of pesticides during storage of the cowpeas. The findings concludes that the levels of some of the residues exceeded the safety limits while some were below the safety limits, suggesting that some of samples of the cowpea were not safe for human consumption as bioaccumulation, persistence, and toxicity of these residues was likely to pose serious health risks to the consumers. Generally, cowpea from the 2016/17 season contained higher pesticide residues than those from the 2017/18 season.