In the process of developing an improved fallow system based on forage legumes, the potential interest of crop-livestock farmers in enhancing soil fertility restoration and dry-season feed supply was assessed during a socio-economic study on 11 farms of settled agro-pastoralists in the subhumid zone of West Africa. Simultaneously, eight farmers in the group participated in simple and largely farmer-managed on-farm experiments testing the establishment of selected forage legumes on fallow land. In addition to agronomic parameters, the participatory approach included an evaluation of the technology by farmers both during farm visits and field days.

With cropping and dry-season feeding strategies increasingly being limited by land availability, the agronomic performance of some of the tested legume species, in particular Stylosanthes guianensis, promised substantial productivity gains once they could be integrated into the traditional fallow system. The major concerns of the farmers were animal health and labour supply for cropping activities, rather than soil fertility and feed constraints. The need for initial weed control within most of the legume species, therefore, limited their acceptability by farmers at this early stage of innovation testing. Nevertheless, farmers' interest grew remarkably in the course of the study. Options for the selection of appropriate species and management practices, which aimed at facilitating the establishment of legumes on fallow land, are discussed as a means of enhancing further adoption of the innovation.

Grain barley was grown either continually or in rotation with fallow in a 12-year experiment. Annual rainfall ranged from 120 to 297 mm. As the water requirement of the crop is 240 mm, growth in most seasons occurred under water stress. The amount of water conserved under fallow was only significant (75–100 mm) in three of the 12 years and only once did the water conserved increase barley yield in the following year. The total grain yield over the experimental period was twice as high in the barley–barley sequence as in the barley–fallow sequence.

Cultiuo continuo de cebada o después de barbecho

Dry matter produced and allocated to the tuber and aerial portions of yam plants (Dioscorea spp) were studied over 3 cropping seasons in the moist forest region of Nigeria, in an attempt to relate dry matter accumulation to vegetative maturity in the crop. The effect of duration of growth of yam on post-harvest dormancy was also studied. Cultivars differed both in the total amount and period of growth when most dry matter was accumulated. A higher proportion of dry matter was allocated to tubers in lower-yielding than in higher-yielding cultivars. It appears that a yam tuber is ‘mature’ almost as soon as it is formed.

Uptake of the major nutrients by maize was determined throughout the growing season. Little phosphorus was accumulated, as reflected in its distribution within the plants, but uptake of labelled phosphorus showed two distinct peaks associated with root development. One fifth of the applied phosphorus was recovered by the plants.

An experiment was conducted during the minor season in Sierra Leone to determine the optimum planting date for a photo-insensitive cowpea cultivar and study the relations between total rainfall and soil moisture available at different growth stages. Cowpeas planted in early September produced the tallest plants and higher grain yields than from other planting dates, since they benefited from 90% of the season's rainfall and made use of stored soil moisture. Average weekly rainfall or soil moisture in the top 15 cm of soil, recorded from planting to 50% flowering, can be used to predict cowpea grain yield.

A study was carried out to identify the factors that contributed to the natural spread and uptake of a rainfed rice variety named Agya Amoah in the Western Region of Ghana after introduction of a small amount (0.5 kg) of seed in 1987 by a small-scale farmer. Fifteen years after its introduction over 73% of rice farmers had grown the variety in the Western Region. Initial awareness of the variety was created by information provided mainly by friends, seeing the variety grown in fields and from relatives. Seed for initial planting of the variety was purchased from other farmers by 67% of farmers, but in the most recent season 77% of farmers used their own saved seed. Annual incremental income per household from the replacement of the previously most widely grown variety with Agya Amoah was estimated to be US $282. The results show that informal systems can result in relatively fast spread and extensive uptake. Local seed systems need to be understood to design appropriate activities that are likely to lead to rapid spread and equitable distribution of introduced varieties, irrespective of characteristics such as wealth and kin.

An experiment on wheat (variety Mexipak) was undertaken for two years at the Experimental Farm to study the effects of soil and foliar application of urea. The results indicated appreciable increases in grain yields due to foliar sprays of urea during both years of the experiment; the spray helped to increase yield-contributing factors such as thousand-grain weight, weight of grains per plant, plant height and dry weight.

Boron treatment was superimposed on half of 48 Amazon cocoa NK-treated plots in four locations across Southern Nigeria. Boron was deficient in soil and leaves of untreated 12-year-old Amazon cocoa, but boron treatment increased bean yield from 13 to 70%. Application of N and K fertilizers reduced the impact of soil-applied boron.

Although the application of small quantities of nitrogen (N) fertiliser has improved cereal yields on low-input farms in semi-arid Zimbabwe, the practice is reported to be laborious and time-consuming by farmers. In an effort to make micro-dosing less labour-intensive and more precise, an ammonium nitrate (AN) tablet, the equivalent of a micro-dose of prill AN (28 kg N ha−1) applied per maize plant, was developed by International Crops Research Institute for the Semi-Arid Tropics in collaboration with Agri-Seeds, Zimbabwe. This study characterized the physical stability, chemical (N% and solubility) and agronomic performance of AN tablets compared with prill AN. Only 10% of tablets broke when dropped from 2 m, showing that they are physically stable and can handle rough treatment. The N content in the tablets (33.3%) was comparable to that in prill AN (34.6%). However, the tablet formulation took twice as long to dissolve than prill AN when placed on a wet soil. Despite this difference in solubility, simple leaching column experiments suggest that less than 2% of the total AN applied was lost due to leaching. Agronomic trials were superimposed on the paired-plot demonstrations used to promote micro-dosing and the conservation agriculture tillage technique of planting basins from 2005 to 2008. Each tillage (plough and basins) plot was subdivided into three sub-plots on which no AN, prill AN and tableted AN treatments were superimposed. Maize was planted and management of plots was left to farmers. Micro-dosing with either prill or tableted AN significantly (p < 0.001) increased maize grain yield by over 40% in all seasons for planting basins. However, on the ploughed plot there was no yield benefit to using either AN formulation in the season with the lowest rainfall (2006–2007). There was no significant difference in grain yield and agronomic N use efficiency between prill and tableted AN formulations except for the 2005–2006 season in planting basins. During this season, in planting basins, tableted AN had significantly (p < 0.001) higher rainwater productivity than prill AN, which translated into greater grain yield. In addition, the maximum benefit to micro-dosing was observed to accrue when combined with water harvesting techniques such as planting basins. An observation supported by the host farmers, who in the second and third seasons chose to apply available basal soil fertility amendments to the basin plots over the flat plots. Thus, AN tablets if available at an affordable price can be used by smallholder farmers to more precisely apply N fertiliser. Future work should focus on the labour issues of micro-dosing, and making cost-effective tablets available to resource-poor farmers and also addressing other limiting soil nutrients.

Conocarpus lancifolius is an ornamental tree planted in Kuwait, resulting in more than 120 t of residual by-products daily. These residues could be utilised as ensiled feed. A total premix of 24 t of silage was prepared in six pilot-scale trench silos for 30 days, after which triplicate samples were taken from each trench silo, which were analysed for nutritional contents and microbial populations. Mean pH value was 4.2 ± 0.12, where mean of dry matter (DM), crude protein, crude fats, crude fibre, organic matter, lactic and acetic acids and total water soluble carbohydrate concentration were 35.10 ± 4.0%, 11.18 ± 0.07%, 2.47 ± 0.21%, 20.85 ± 0.95%, 19.53 ± 0.53%, 4.95 ± 0.32%, 1.47 ± 0.01% and 20.86 ± 0.56% on DM basis, respectively. Means of aerobic bacteria, fungi (yeast and moulds) and lactic acid bacteria counts were 1.8 ×104 ± 0.15, 1.1 × 104 ± 0.09 and 7.3 × 108 ± 0.12 colony forming units per gram of fresh silage, respectively. An animal performance trial was conducted on 60 Holstein Friesian heifers with initial live weights ranging from 262 to 275 kg, grouped in six dietary treatments for a 148-day feeding trial. The diets contained different ratios of Conocarpus silage, which ranged from 10 to 60% on DM basis partially replacing conventional roughage (alfalfa hay, straw). DM intake of heifers ranged between 11.40 ± 2.14 kg and 13.61 ± 2.54 kg. Daily live-weight gain ranged from 0.99 ± 0.38 kg to 1.20 ± 0.31 kg. From the results, Conocarpus silage could be suggested as a replacement for conventional roughage in rations for growing heifers.

Colour development in fruits of dark purple eggplant cultivars was greatly influenced by temperature conditions. During the cool season, colour development was much slower than during the hot season, corresponding to slower fruit growth and much lower final weight. There were varietal differences in seasonal influence on the distribution of various colour shades, both during fruit growth and at harvest. Soil heating during the cool season improved fruit colour.

We developed a protocol for comprehensive evaluation of nutrient management (NM) technologies for production of eggplant taking its yield, produce quality, profitability, energy balance and environmental sustainability in terms of upkeeping soil quality as the goal variables. Fifteen NM technologies comprising of three sources of nutrients viz., organics [vermicompost (VC), farmyard manure (FYM) and mustard oil cake (MOC)], inorganic fertilizations [recommended N–P–K at the rate of 100–22–42 kg ha−1 and 150% of recommended N–P–K (NPK^)] and their selected combinations were tested for growing the plants. Integrated NM technology was proved to be socio-economically sound and environment-friendly practice. It helped to upkeep soil quality by improving soil organic carbon stock, microbial biomass carbon, bulk density and available nutrients in soils. Combining all the parameters by employing non-parametric evaluation of regression factor scores through principal component analysis, the NM technology of VC3 Mg ha−1+NPK^ was found to be the best when considering the marketable fruits (12.27 Mg ha−1), economic return (benefit-cost ratio 3.3; marginal rate of return 8.7), energy conserving efficiency (net energy 113.8 GJ ha−1), soil and crop quality for human welfare. Only organics were less productive and profitable, and energetically less efficient than the integrated and inorganic NM systems and as such may not be sustainable for eggplant production in subtropical India.

India is the world's dominant producer of crude Mentha arvensis oil, and exporter of its processed derivative, natural menthol. This status has been achieved through superior product price competitiveness resulting from progressive agronomic improvements that include a transition from cultivation of this mint as a semi-perennial to an annual crop. This paper describes and analyses recent developments in Indian M. arvensis cultivation.

Observations were made during 1998/99 and 1999/2000 in the fields of 295 farmers in the central Indo-Gangetic plains area. The criteria recorded included: mint cultivars used; the planting, weeding, irrigation, pesticide application and harvesting schedules; crop health in relation to diseases and pests; yields of the harvested herb and the distilled essential oil; the oil menthol content; and the net income.

Most of the farmers used the cultivar, Kosi. The performance and returns of Kosi transplanted in April had proved superior to Kosi and Shivalik suckers and to transplanted Shivalik. The returns from late-transplanted Kosi were in the range of Rupees (Rs) 25 000 to Rs 40 000 ha−1 (Rs 50≈US$1), similar to those from Kosi suckers and much higher than for both transplanted and suckers of Shivalik. This survey revealed that rotations of rice (Oryza sativa) with chickpea (Cicer arietinum) and mint, and pigeonpea (Cajanus cajan) with wheat (Triticum aestivum) and mint could be profitable in the central Indo-Gangetic plains. They also conserved inputs and were preferable to the conventional rice-wheat rotation. A re-survey in the summer of 2002 confirmed that recommendations made to farmers have led to the adoption of the Kosi and Himalaya cultivars in 80% of the survey region and that 70% of mint cultivation in the area occurs in the summer season.

The Adaptive Research Planning Team in Luapula Province (ARPT-LP) is one of nine provincial teams in Zambia conducting farming systems research within the Research Branch of the Ministry of Agriculture and Water Development. ARPT-LP has been relatively successful in developing a partnership with farmers, involving them in both the planning and implementation of the team's research programme. This paper examines the formal and informal occasions on which farmers have been involved in the team's activities, with examples to illustrate how farmers' opinions have influenced decisions made by ARPT-LP. The factors which have influenced the frequency and quality of the scientists' interaction with farmers are discussed.

An appreciable loss of gaseous N from added urea was recorded in two sub-tropical soils of East Pakistan under laboratory controlled conditions, markedly accentuated by the presence of decomposable organic materials which increased ammonification and tended to decrease nitrate accumulation. The addition of bonemeal to the soils had little effect.

Climatic change affects global agriculture and is a severe threat to global food security due to variability of the three factors measuring climate change (CO2, temperature and precipitation) with temperature being the most crucial one. Wheat is severely affected by high temperatures with reproductive and grain-filling phases being most sensitive, impacting grain number, size and weight. Seed size and weight are the key agronomic traits subjected to artificial selection and involved in the domestication process since the origin of agriculture. Three genotypes Banks, EGA Gregory and Fang-60 with the latter known to be heat tolerant were grown under glass house conditions and subjected to heat stress for 3 days during early- (11–14 dpa – days post anthesis) and late- (27–30 dpa) grain filling stages in a mutually exclusive fashion. The impact of heat stress during early- and late- grain filling on the four major grain characteristics, thousand grain weight (TGW), grain length, grain width and grain thickness was assessed. The tolerant genotype Fang-60 exhibited significantly higher TGW during early-grain filling heat stress than the control possibly due to an ability to exploit the accelerated release of fertilizer under high temperature. Banks and EGA Gregory were moderately tolerant to susceptible to heat stress, respectively, at early- and late-grain filling with Fang-60 being tolerant to both early- and late- grain filling heat stress. This study confirms the availability of significant genetic variation in heat stress response in wheat that might be exploited to adapt wheat to higher growth temperatures.

The relations between sugar content and certain features of growth were followed in 16 sugarcane varieties during two crops. High sugar content was promoted by the absence of tillering during cane elongation, by a high leaf blade to joint weight ratio, by a long phyllochron, and perhaps slightly by a long life span of leaves. To combine high yield with high sugar content it is important to have a high tiller number early in growth, which appears to be promoted by delayed onset of cane elongation, small initial leaf size, and an upright leaf habit. To combine a small initial leaf size with a high leaf blade/joint weight ratio during elongation requires a large increase of leaf size during growth.

Despite large visual differences in size and form of shoot and root systems of young clonal plants and of older seedlings, there was no convincing evidence that tea plants, brought into bearing by pegging, are necessarily more susceptible to water stress than similar plants that have been pruned, though the sap tension in pegged plants of one clone was often greater than in similar pruned plants. Further studies are needed to show whether this is the case in drier areas, but differences in responses to dry conditions by individual clones appear to be of greater significance.

Growth and the partitioning of dry matter and nitrogen were studied in winged bean ‘SLS-40’ grown with single stake supports at two sites in Sri Lanka. Plant parts (leaves, petioles, stems, roots, nodules, flowers, green pods, mature seeds, and mature pod-walls) were collected periodically, if present, for up to 32 weeks after emergence. Slow growth up to the seventh week was followed by rapid growth (2.8 g plant−1 day−1) for the next 15–17 weeks. Little leaf senescence was observed and the nitrogen content of the leaf tissue remained close to 45 mg N g−1 throughout growth. The rate of nitrogen accumulation was 2.3–2.7 kg N ha−1 day−1 between weeks 13 and 32. The final accumulation of nitrogen in the above ground material was 280 to 312 kg N ha−1, only 34% of that being in the mature seed. The harvest index for dry matter was 17.5–20% and the dry seed yield almost 2 t ha−1.

The shoot regrowth vigour of sugarcane varieties having contrasting phosphorus (P) efficiency was evaluated under varying soil P availability. The P-inefficient (IAC91–1099 and IACSP94–2101) and -efficient (IACSP94–2094 and IACSP95–5000) sugarcane varieties were grown under low (25 mg P kg−1 soil) or high (400 mg P kg−1 soil) P supply at planting. After 90 days (first cycle of growth), the shoots were harvested and regrowth was studied 70–75 days later by evaluating photosynthesis, leaf area formation, biomass production and P uptake. The shoot dry matter (DM) of sugarcane regrowth subjected to a low P supply was genotype-dependent, with the P-efficient varieties exhibiting greater values than the inefficient ones. This result was explained by the greater efficiency of IACSP94–2094 and IACSP95–5000 in acquiring P rather than P utilization efficiency for shoot biomass production. The root P stored during the first cycle of growth would represent only a minor fraction (< 20%) of the total P content in the shoots at the end of the regrowth period. Thus, we argue that the improved shoot P uptake of the P-efficient varieties was related to their ability to sustain P acquisition after harvesting rather than to the remobilization of root P reserves. Moreover, our data revealed that net CO2 assimilation per leaf area was not associated with differential performance among varieties under P deficiency, suggesting a more critical role of total leaf area in photosynthate supply for sugarcane regrowth. In conclusion, sugarcane regrowth is improved in P-efficient varieties under P deficiency conditions, a finding of practical relevance as such ability might benefit the productivity and the longevity of sugarcane ratoons in low P tropical soils.