A major problem faced by small-scale farmers in northern Ethiopia is reduced crop yield due to increasing soil degradation resulting from repeated tillage and inadequate agronomic management practices. These practices have left soils and rainfed crops susceptible to hazardous climatic events such as droughts. Sustainable farm practices such as minimum tillage and surface residue retention have been shown to improve soil health and crop productivity. The objectives of this field study were thus to evaluate the impacts of conservation agriculture (CA) practices on crop yield and economic productivity over 6 years in the eastern Tigray region of northern Ethiopia. Using a barley–wheat rotation from 2010 to 2016, the applied treatments were (i) permanent raised beds (PRB); (2) semi-permanent raised beds (SPB) and (3) conventional tillage (CT). Average barley and wheat biomass and grain yields in PRB and SPB treatments were consistently greater than yields under CT each year. In addition, the highest marginal rate of return was obtained in PRB and SPB compared to CT in all years (2010–2016). These results suggest that the CA practices of PRB and SPB can improve crop yield and profit compared to CT practices in the Tigray region.

Groundnuts (Arachis hypogaea L.) have been found to be one of the most promising additional cash crops for diversifying Sudan agriculture. Three hundred and thirteen agronomically distinct forms have been separated from 171 varietal samples, and 121 short-maturing upright bunch types and 49 long-maturing spreading bunch types have been tested in a series of trials over several years in four climatic regions. Among upright bunch varieties, PJ121070 and Large Natal 142 appeared to be the best selections as oil and confectionery types respectively, and among spreading bunch varieties, MH.372, Beladi Bunch and NJ37 for oil, confectionery kernels and unshelled nuts respectively. A hybridization programme was started in 1959 to improve the existing varieties of groundnuts and to produce non-germinating upright bunch varieties for growing in the heavy clay soils. Inheritance studies indicated the dominance of an alternate pattern of branching, prostrate plant habit and long maturity. Dominance of testa colours was in the order of purple–red–russet brown–light brown–white. Recessive albino seedlings were observed only in crosses involving different branching pattern. There appeared to be no association between the various characters studied except maturity period, which was related to branching pattern and growth habit.

Four trials are described on the effects of spraying and cultural practices on pests and yields of seed cotton. Precropping with sorghum or beans after opening from a ley did not reduce yields of cotton compared to the recommended practice of ploughing a ley 6 weeks before sowing, but late ploughing and late sowing reduced yields. Nitrogenous fertilizer after a successful ley did not increase yields, but multiple sprays (up to twelve) significantly increased them over the recommended standard four spray regime, and reduced the percentage of stained seed cotton. In general cultural practices did not affect the level of pest attack, but DDT spraying gave excellent control of Heliothis armigera, while dimethoate prevented the build up of red mite (Tetranychus telarius) and gave excellent control of tea mite (Polyphagotarsonemus latus) in the multiple spray regimes.

The use of tropical grass–legume mixtures containing the grasses Brachiaria decumbens or Andropogon gayanus associated with a mixture of several herbaceous legumes was tested on farms in the rainforest area of Pucallpa, Peru. Pastures were established by farmers using manual labour and without fertilizer in previously deforested areas covered with secondary growth. The pastures, together with their grass-alone control, were incorporated by farmers into the normal paddock rotation, and were grazed by dual-purpose cattle of mixed breeding. Cows were milked once daily by hand and with their calves at foot. Following a training period, farmers kept records of milk yields. Frequent and unannounced visits at milking time by the research team were used to verify milk yields and to annotate events such as calving, drying out, sales and others. Across farms and years, grass–legume mixtures significantly outyielded grass-alone pastures by 9%. Milk yields on the mixed pastures were examined further by stepwise regression. A positive and significant effect of the proportion of crossbred cows in the herd was established, whereas soil quality (evaluated by the percentage of aluminium saturation) had a negative impact on milk yields. Two of the farms, which for different circumstances had poorer than average animal and pasture management, also had a significantly negative effect on milk yield. The interactions between animal and pasture management, and regional infrastructure are discussed. It is concluded that grass–legume mixtures increased milk yields on farms. Nevertheless, it is also hypothesized that they may have a more restricted niche than anticipated and that their adoption may be highly sensitive to the overall economic context of the region.

Castor beans grew well in sandy soils in U.A.R. where field crops had previously failed to produce good yields. Calcium nitrate up to 300 kg. per feddan resulted in increased yields of seeds and oil in a two-year experiment. Better yields were obtained by increasing the number of plants up to 3 per hill at distances of 45 cm. apart. The oil percentage and other properties were not influenced by nitrogen fertilizers or plant density.