Successive droughts in Kenya compounded with other socio-economic constraints have led to persistently unstable and declining agricultural productivity in semi-arid eastern Kenya. This has given rise to the need to find coping strategies that would include growing alternative crops that are drought tolerant and thus suitable for the areas. Research in Kenya and elsewhere has shown that sorghum (Sorghum bicolor L. Moench) has the potential to end severe food insecurity in ASALs due to its tolerance to drought and ability to thrive under a wide range of soils. However, research and government policy in Kenya have shown a continual inclination to maize production in these areas though the crop is regarded a high risk option due to poor adaptation especially to the low rainfall. This paper reviews the potential of sorghum for improving food security in ASALs of Kenya with specific focus on semi-arid eastern Kenya. This will contribute to the ongoing debate to inform private and public sector policy and investments for increasing production of sorghum and other drought tolerant crops in the ASALs as a way of alleviating food insecurity and poverty.

This study aimed to evaluate the effect of Farm Yard Manure (FYM), mineral fertilizers (nitrogen and phosphorus), and their combination on the production of Gadam sorghum in a Kenya Semi-arid region of Makueni and Machakos counties. The first experiment evaluated the response of sorghum to N and P application at four levels (0, 25, 50, 75 kg ha-1) whereas the second evaluated the response of sorghum to the combined application of FYM (0, 5, and 10 tons ha-1) and N and P fertilizer (0 and 50 kg ha-1). Nitrogen application enhanced sorghum yields more than phosphorus addition. Combining N at 75 kg ha-1 and P at 50 kg ha-1 gave the highest sorghum grain yield in Kampi ya Mawe which was 135% higher than the control. In Katumani, combining 50 kg ha-1 N and 25 kg ha-1 P gave the highest mean grain yield, which was 68.3% more than the untreated control.

East African Sandalwood (Osyris laceolata) is an important tree species used in perfumery and pharmaceutical industries. In Kenya, the tree is illegally poached and smuggled mostly to India as a substitute for Asian sandalwood. Therefore, there is a need to domesticate E. A. sandalwood to ease pressure on natural stands. The aim of this study is to determine ecological factors influencing Osyris oil yield and quality to guide the selection of provenances for on-farm domestication. Soil and woody samples were obtained from 12 provenances and used for soil and oil analysis, respectively. The results showed that only tree age significantly influenced the oil yield (r = 0.31, p = 0.04 ). The GC-MS quality results recorded nine common and most abundant compounds across the study sites. These were Z-alpha-trans-bergamotol, alpha bisabolol, lanceol cis, beta bisabolene, alpha santalol, beta santalol, cis-alpha-copaene-8-ol, isopropyl myristate, and isopropyl palmitate. Baringo and Mbooni provenances had the highest number of compounds (8), followed by Homabay (7) while the majority (Chyulu, Kitui, Loita, Maralal, Marsabit, Muranga, and Narosura) had six and Ol Donyo Sabuk and Namanga had the least (5). The species diversity is therefore important for breeding, domestication, and conservation purposes.

This study investigated the effects of biochar and manure applied singly or together on soil biochemical properties, Casuarina equisetifolia seedling growth and seedling quality. Therefore, a nursery experiment consisting of Prosopis juliflora biochar and cattle manure treatments at 0% (control), 10% biochar, 20% biochar, 10% manure, 10% biochar + 10% manure, and 20% biochar + 10% manure was conducted. Generally, biochar containing treatments recorded higher P concentrations; where the combination of 20% biochar and 10% manure gave the highest phosphorus concentration, which was 137.3% above the control. Nitrate concentrations were higher in manure treatments than the control by 122.9%. As a result of C. equisetifolia's ability to fix nitrogen, nitrates concentration in the control increased from 0.016 ppm at the onset of the experiment to 2.18 ppm at the end the experiment. There was also a general increase in pH with biochar and manure application. Seedlings treated with 10% manure recorded the highest collar diameter and height which was 36.4 and 27.4% above the control respectively while treatments with biochar alone recorded the lowest seedling collar diameters. Seedling quality as observed using the shoot/root ratio showed that sole biochar treatments had the recommended range of <3:1. These results suggest that the use of biochar and manure enhances nitrogen and phosphorus availability which are crucial for production of seedlings that grow significantly faster than seedlings raised from forest soil only.

Improving nutrient management of soils is important in subsistence farming systems in the tropics due to declining soil fertility resulting from continuous cropping coupled with inadequate nutrient replenishment. Balancing nutrient inputs with crop removal is crucial in reducing the build-up of nutrients and minimises nutrient losses through different pathways, thus reducing the cost of production. This study aimed at evaluating the effect of N and P fertiliser on sorghum N uptake at Kampi ya Mawe (KYM) in Makueni County and Katumani (KAT) in Machakos County, Kenya. Two factors (nitrogen and phosphorus) each at two levels (0 and 75 kg ha-1) were evaluated, resulting in four treatments, each replicated thrice. At KYM, N content in sorghum tissues increased by 24.2% in comparison with the control following application of N at 75 kg ha-1. At KAT, plots amended with N and P at 75 kg ha-1 resulted in the highest N content in sorghum tissues at the three sorghum development stages assessed. At the seedling stage, an increase of 18.8% was observed. Sole N application led to an increase in N content in sorghum tissues of 17.6% at the seedling stage. A positive linear relationship between NO3-N and N content in sorghum tissues was also observed. The study showed that soil N uptake was higher in the early growth stages of sorghum. The results of this study are essential to farmers and extension officers as a guide to ensure timely fertiliser application to ensure optimum utilisation of nutrients during crop growth.