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Background. Taro (Colocasia esculenta) is one of the underutilized crops in Kenya, grown under a wide range of environmental and edaphic conditions. This crop has exceptional dietary value and numerous culinary applications due to its edible leaves and corms. However, the mineral nutrient composition of taro in Kenya is still not well known due to a lack of scientific information concerning production. Objective. To determine the proximate composition and mineral profile of taro under different watering regimes and planting densities in Embu, Kenya. Methodology. A study was conducted at the Kenya Agricultural and Livestock Research Organization (KALRO) – Embu Research Centre, during the long rains (LR) 2021, and short rains (SR) 2021/2022. A factorial experiment with a split-plot layout arranged in a completely randomized block design was adopted. The watering regimes (100 %, 60 %, and 30 % based on the field capacity (FC)) were the main factor while the sub-factor was the planting density, with three replications. The planting densities used were 0.5 m × 0.5 m (40,000 plants ha-1), 1 m × 0.5 m (20,000 plants ha-1), and 1 m × 1 m (10,000 plants ha-1), representative of high, medium, and low planting densities respectively. Proximate analysis and mineral content were determined. Results. Significant differences (P < 0.05) in seasons were noted for protein, fibre, potassium, calcium, sodium, and zinc in the taro corms. The high carbohydrate content observed in this study (35 – 39 %) indicates that taro tubers are a good source of nutritional energy. Potassium (> 5000 mg kg -1) and magnesium (> 1000 mg kg -1) were the most prevalent mineral elements in taro corms and leaves, with copper (< 25 mg kg -1) being the least prevalent. Implications. Consumption of nutrient-rich foods such as taro helps the body to utilize the necessary nutrients to combat malnutrition and promote food security in rural communities. Conclusion. Taro leaves can be recommended as leafy vegetables as they are good sources of potassium, magnesium, calcium, manganese, iron, copper, and zinc; and the corms have low fat and protein content, high calorific energy, and high carbohydrate content. Taro represents one of the main sources of energy in many parts of the tropics and its production can be recommended in sub-humid areas in Kenya.

Background. Taro (Colocasia esculenta) can be grown in a variety of environmental and edaphic conditions, but it is most typically grown in wetlands. The optimal conditions for its growth are two water regimes i.e., waterlogged or flooded conditions to dryland or unflooded conditions. An important criterion in crop yield is water use efficiency (WUE), and it has been suggested that crop production per unit of water used can be increased. Objectives. To determine the WUE of taro in Kenya’s sub-humid environment under different watering regimes and planting densities. Methodology. A study was conducted at the Kenya Agricultural and Livestock Research Organization (KALRO) – Embu Research Centre, during the long rains (LR) 2021, short rains (SR) 2021/2022, and long rains (LR) 2022. A factorial experiment with a split-plot layout arranged in a completely randomized block design was used. The main factor was the irrigation levels while the sub-factor was the planting density, with three replications. The three irrigation levels were at 100 %, 60 %, and 30 % based on the field capacity (FC). The planting densities used were 0.5m × 0.5m (40,000 plants ha-1), 1m × 0.5m (20,000 plants ha-1), and 1m × 1m (10,000 plants ha-1), representative of high, medium, and low planting densities respectively. Results. The WUE was influenced by season and watering regime (P < 0.05). The 30% FC had the highest WUE with the 100 % FC having the lowest. The high WUE under 30 % FC (19.40 kg ha-1mm-1) was associated with the high biomass (1.97 kg) and low water use (2269.41 mm) recorded under limited water conditions. The medium (1m × 0.5m) planting density attained the highest WUE (12.16 kg ha-1mm-1) with the high planting density (0.5m × 0.5m) having the lowest (10.65 kg ha-1mm-1), though no significant differences were recorded. Implications. The varying watering regimes and planting densities in this study have different capacities to utilize the supplied water. The total taro biomass increased with decrease in water supplied and in turn maximized the water use efficiency. Conclusion. To achieve the highest yield per unit of water consumed, a watering regime of 30 % FC and a planting density of 1 m × 0.5 m (20,000 plants ha-1) is recommended.

Background. Pedology is the study of soil genesis in its natural state. One way to assess the strength and productivity of a scientific field is to measure the number of publications over time. The number of soil papers published worldwide has almost doubled in the last ten years. However, that has not been the case in Eastern Africa, where this review is conducted. The scarcity of research in pedology motivates this study. Objectives. To review and analyze trends of publications in pedology/soil survey for the last ten years in (2010 - 2019) in Eastern Africa. Methodology. A search of scientific literature using Google and Google Scholar was conducted from 2010 - 2019. The search terms used were - soil survey, soil characterization, pedological characterization, and each of the Eastern African countries (Ethiopia, Kenya, Uganda, Tanzania, Rwanda, and Sudan). We then scrutinized the abstracts to find quantitative data on geographical locations. Additional articles were reviewed by checking through the reference lists of relevant studies in the peer-reviewed articles. Results. 56 scientific articles, 3 MSc/PhD theses reports, and 4 project reports/ proceedings were included for the full review. Out of this, 39 journal papers were identified and reviewed based on the years they were published, and the countries where they were published. Most articles were published in 2018. The data was then split into two segments, from the years 2010 - 2014 and 2015 - 2019. Between the years 2015 to 2019, a total of 36 articles were published compared to the years 2010 to 2014 where a total of 15 articles were published. This shows a slight increase in publications for the years under study. From the 56 articles, Ethiopia records the highest number of published articles from various journals having a total of 25 papers constituting 45% closely followed by Tanzania, having 27% equivalent to 15 papers. Kenya comes third in the overall ranking at 13% with 7 papers. The last three countries are Sudan, Rwanda, and Uganda with 10%, 3%, and 2% respectively. Implications. The results suggest that pedology seems to be a disappearing skill in the Eastern Africa region. Though there has been a spike in publications from 2015-2018, the current situation must be improved as there are limited publications from 2010 - 2019. Conclusion. The study shows that there have been a low number of publications in Eastern African countries. Ethiopia which has the highest number of publications shows the most promise in soil pedology publications. There is a need for an increase in pedology research which is important for agricultural production and land use planning.

The principle objective of terracing is to reduce runoff and soil loss but it also contributes to increasing the soil moisture content through improved infiltration. A field experiment was conducted in Suswa, Narok County during the short and long rain seasons of 2013-2015 to assess the effect of terracing on crop yields. A randomized complete block design was used with maize and beans as the test crops. The study examined maize plant height, leaf area index (LAI), above ground biomass yields, number of bean pods and grain yields in the upper (U), upper middle (UM), middle (M), lower middle (LM) and lower (L) terrace, slope positions with farmers’ fields where terraces were not maintained were used as the control. The results showed that yields were significantly (PLM>UM>M>U, with values ranging from 7.2 t ha-1 to 3.0 t ha-1 for maize and 1374 kg ha-1 to 306 kg ha-1 for beans. Significant differences (P

Conservation of soil moisture through tillage practices is an important management objective for crop production in semi-arid areas. A study to evaluate the effects of tillage practices on maize and bean yields was conducted in Mwala Sub County, Eastern Kenya, in the long (LR) and short rains (SR) of 2012/13. The tillage treatments were: Disc Ploughing (DP), Disc Ploughing and Harrowing (DPH), Ox-ploughing (OX), Subsoiling – Ripping (SSR), Hand hoeing with Tied Ridges (HTR) and Hand hoeing (H) only. There were three cropping systems of Sole Maize (SM), Sole Bean (SB) and Maize - Bean intercrop (M + B), which were investigated in a Split-Plot Design field experiment with four replications. Data on maize and bean yield and yield components were monitored throughout the four cropping seasons. Maize plant height, leaf area and leaf area index, maize and beans grain and biomass yields were significantly affected by tillage (P < 0.05). No significant effect of cropping systems on the maize height was observed. Higher maize grain yields (P < 0.05) were obtained in the sole maize plots in LR 2012 (5.01 Mg ha-1), SR 2012 (4.19 Mg ha-1) and in the SR 2013 season (2.82 Mg ha-1). A three - season bean grain yield average by tillage shows that DPH > SSR > DP > OX > HTR > H, with values ranging from 0.75 Mg ha-1 to 1.46 Mg ha-1 (P < 0.05). Intercropping reduced the seasonal means of bean grain yields (P < 0.05) with a 54 % decrease by intercropping (0.73 Mg ha-1) compared to the sole bean (1.6 Mg ha-1). Thus, the DP and DPH improved crop yield and yield components and can be recommended as tillage practices in the semi-arid region.

Low crop yields in the semi arid areas of Kenya have been attributed to, among other factors, low soil fertility, low farm inputs, labour constraints and inappropriate tillage practices that lead to pulverized soils. The aim of this study was to determine the effects of legume cover crops (LCC) on soil properties and maize growth in the semi arid area of Machakos District, Kenya. The study was undertaken in farmers’ fields. The field experiments were carried out in a RCBD with four treatments each replicated four times during the 2008 long (LR) and short rain (SR) seasons. The treatments were T1 = maize + dolichos (Lablab purpureus) + subsoiling; T2 = maize + dolichos + no subsoiling; T3 = maize alone + no subsoiling; T4 = maize alone with subsoiling). Results from the field experiments showed that rainfall amount and its distribution affected the growth and yield of dolichos and maize. There were significant differences in ground cover between the treatments at P ≤ 0.05 in all the different weeks after planting when measurements were taken. The penetration resistance in all the plots ranged from 3.83 - 4.18 kg cm-2 with treatment T4 having the highest and treatment T1 lowest penetration resistance. There were also siginificant changes in soil N in plots which were under dolichos compared to plots without dolichos. The results obtained in this study also indicated that subsoiling in combination with dolichos had the greatest potential of improving soil properties and crop yields in semi arid environments of Kenya.