Physiological determinants of cowpea seed yield as affected by phosphorus fertilizer and sowing dates in intercrop with millet

The interaction of cowpea (Vigna unguiculata (L.) Walp.) cultivars with management factors and environments was analyzed in terms of parameters of a simple physiological model. In one set of experiments seven cultivars were sown at three rates of phosphorus (P) fertilizer (0, 8 and 16 kg P ha−1). In another set, five cultivars were sown on two dates relative to sowing of millet (Pennisetum glaucum (L.) R.Br.). All experiments involved factorial combinations of management and cultivar treatments, and were conducted in 1988 and 1989 at two sites in western Niger. Seed yield, shoot dry matter, vegetative (Dv) and reproductive (Dr) durations were determined and crop growth rate (C) and partitioning (p) to seed estimated Application of P increased seed yield by increasing C. As sowing was delayed from 1 to 3 weeks after the millet was sown, there was a reduction in seed yield due to decreases in C, Dv and Dr. Variation in cultivar performance across years was mainly a function of C and partitioning. In both experiments the C of the landrace Sadore Local was greater than that of other cultivars, although the partitioning to seed of this cultivar was unstable due to variable control of insect pest damage It is concluded that the primary causes of G × E interactions were differential canopy development and insect damage effects. Therefore in the development of cowpea cultivars for intercropping with millet, emphasis should focus on light capture capabilities. Improved yields would then seem possible with most cultivars, providing insect damage is controlled

Integrated Nutrient Management: Concepts and Experience from Sub-Saharan Africa

In Africa, 28 percent of its landmass, 874 Mha, is potentially suitable for agricultural production. Of the potentially suitable agricultural land, 34 percent comprises arid and semiarid lands (ASAL) that are too dry for rainfed agriculture. The semiarid regions have a shortened length of growing period (75-129 days) compared to the subhumid (180-269 days), and the humid (>270 days) zones. The dynamics of agroecosystems show that the farming systems practiced have gone through diverse changes from traditional shifting farming systems to permanent and intensified arable and mixed farming systems. The changes are coping strategies to respond to the environment, and its changing biophysical and socioeconomic circumstances..

Combining soil fertilization, cropping systems and improved varieties to minimize climate risks on farming productivity in northern region of Burkina Faso

Background In search of options to cope with climate change and variability, a trial combining fertilization and improved varieties of millet and cowpea (intercropped or as sole crop) was conducted on three sites (Lemnogo, Tibtenga and Ramdolla) in the northern region of Burkina Faso. The application of cattle manure (3 t ha−1), micro-dose (3 g hole−1 equivalent to 62 kg ha−1) of a mineral fertilizer composed of 14 % N, 23 % P2O5 and 14 % K2O (NPK), their combination and a control (no manure and no NPK) as four soil fertilization options, two improved varieties of millet (SOSAT-C88 and IKMP5), two varieties of cowpea (KVX 396-4-5-2D and KVX 61-1) and two cropping systems (millet–cowpea intercropping, sole crop) were tested on-farm for two seasons (2013 and 2014). During the third season a survey was conducted on the acceptability by farmers of the tested combinations as a way of buffering or coping with rainfall variability. Results Two-year trial revealed that the combination of manure and NPK applied to the intercropping of millet and cowpea significantly increased crop production (land equivalent ratio = 1.83 ± 0.18 and 1.78 ± 0.20, intercropping millet variety IKMP5 with cowpea KVX 61-1 and intercropping millet variety SOSAT-C88 with cowpea KVX 396-4-5-2D, respectively). During erratic rainfall year, intercropping millet IKMP5 and cowpea KVX 61-1 performed the best, while under well-distributed rainfall conditions, intercropping millet SOSAT-C88 with cowpea KVX 396-4-5-2D displayed higher production, respectively, for millet and cowpea. Some varieties were not well accepted by most farmers (based on a survey of 36 farmers) mainly because of loss in grains before harvest for millet IKMP5 (97 %) and high grain attacks by insects in storage for cowpea KVX 61-1 (89 %). The alternative for farmers rejecting these varieties could be the intercropping of millet SOSAT-C88 and cowpea KVX 396-4-5-2D fertilized with manure. Conclusions Making weather forecasts and related agronomic advices available to farmers in this region will allow them to better plan their agricultural practices such as mineral fertilizer application and will also be a great move toward climate-smart agriculture. Developing more performant storage measures that drastically reduce insect attacks for some of the tested varieties (cowpea KVX 61-1, for instance) could contribute to promoting their adoption

Simulated weather variables effects on millet fertilized with phosphate rock in the Sahel

The Sudano–Sahelian agroecological zone is characterized by low and variable rainfall regimes and P deficiency. The present study complements previous research efforts and the objective was (i) to use the Newhall Simulation Model (NSM) to characterize three ICRISAT research sites, and (ii) to use output of NSM to develop an empirical model to guide efficient use of rainfall and fertilizers. The results show that length of the periods that rainfall exceeded evapotranspiration was larger in Bengou than in Gobery and Sadoré. Total positive moisture balance during the three growing seasons was 85.7 mm at Bengou and 19.7 mm at Sadoré. The model explained 52% of the variability in millet yields based on curvilinear response to P fertilizer, standardized May–June (Rmj) rainfall, and the number of wet days in the year (BW3). Yields appear more sensitive to BW3 than to Rmj. Their respective elasticity coefficients (E c ) were 0.62 and 0.09. Assessment of the model using R2=0.76 and the D-index = 0.85 showed reasonable agreement between model estimation and actual field yields. The study demonstrates the application of simulation models as a cost-effective means in terms of time and funds to agronomic researc

Agronomic evaluation of two unacidulated and partially acidulated phosphate rocks indigenous to Niger

A field study was conducted on a sandy soil in Niger to evaluate the agronomic effectiveness of various P fertilizers for millet production during 1985 to 1987. The P fertilizers tested were two finely ground phosphate rocks (PR) indigenous to Niger (Tahoua and Parc W rocks), PR partially acidulated with H2SO4 at 50% acidulation level (PAPR), single superphosphate (SSP), and triple superphosphate (TSP). In 1985, application rates were 0, 6.5, 13.0, and 19.5 kg P ha−1 for each of the P fertilizers. In 1986, half of the plots received the same rates of P as in 1985 and half of the plots received no additional P. In 1987, P additions were repeated only in half of the plots that received P during 1986. A significant (P = 0.05) millet response to P was observed in all the trials. The major findings of this study were: (i) finely ground Tahoua PR was more effective than Parc W PR because of its higher reactivity and was 82 to 91% as effective as SSP for millet production in both the initial and two subsequent seasons; (ii) partial acidulation of Parc W PR can significantly increase its agronomic effectiveness in the first year, but not in terms of residual effect; (iii) partial acidulation was not a desirable technology for increasing the effectiveness of Tahoua PR, because its high Fe2O3 plus Al2O3 content resulted in a product containing relatively low amounts of water-soluble P; and (iv) over a period of 3 yr, one initial application of a large dose of P fertilizer was found to be more effective than three small annual applications in terms of total grain productio

Fertilizer microdosing and “Warrantage” or inventory credit system to improve food security and farmers’ income in West Africa

The fertilizer microdosing technology deals with the application of small quantities of fertilizers in the planting hole, thereby increasing fertilizer use efficiency and yields while minimizing input costs. In drought years, microdosing also performs well, because larger root systems are more efficient at finding water, and it hastens crop maturity, avoiding late-season drought. Recent research found that solving the soil fertility problem unleashes the yield potential of improved millet varieties, generating an additional grain yield of nearly the same quantity. Recognizing that liquidity constraints often prevent farmers from intensifying their production system, the warrantage or inventory credit system helps to remove barriers to the adoption of soil fertility restoration. Using a participatory approach through a network of partners from the National Agricultural Research and Extension Systems (NARES), non-governmental organizations (NGOs), farmers and farmer groups and other international agricultural research centres, the microdosing technology and the warrantage system have been demonstrated and promoted in Burkina Faso, Mali, and Niger during the past few years with encouraging results. Sorghum and millet yields increased by up to 120%, and farmers’ incomes went up by 130% when microdosing was combined with the warrantage system. This chapter highlights the outstanding past results and the ongoing efforts to further scale up the technology using Farmer field schools (FFS) and demonstrations, capacity and institutional strengthening, private sector linkages and crop diversification amongst other approache

Uses and vulnerability of ligneous species exploited by local population of northern Burkina Faso in their adaptation strategies to changing environments

Background Arid and semi-arid areas of West Africa are highly subject to climate change effects. This is combined to other drivers such as population growth and livestock number increase. To cope with such changing environment, endogenous adaptation strategies of poor local communities rely on the use of natural resources through empirical knowledge. Unfortunately, these knowledge and practices are insufficiently known to policy makers, and this hampers their consideration in the elaboration of adaptation strategies. A household survey was conducted in the Sillia village in northern Burkina Faso using semi-structured interviews. This study identified most used (preferred) species in this changing environment together with their ethnobotanical use value (VUET). Results Overall, 86 ligneous species were listed in seven (7) use categories: human nutrition, fodder, fuel, traditional medicine, handicraft, construction and trade. From the 86 species, 11 appeared the most preferred by local population (VUET ≥ 6). Except Piliostigma reticulatum and Boscia senegalensis, all these species were part of the 21 very vulnerable species as revealed by the study. Tamarindus indica, Balanites aegyptiaca, Lannea microcarpa and Vitellaria paradoxa are the first most preferred species (VUET ≥ 7) and also most vulnerable (IV > 2.5). In this changing environment, Cassia sieberiana, Combretum micranthum, Balanites aegyptica have, for instance, become the main species used in traditional medicine replacing Ximenia americana, Coclospermum tinctorim, Maytenus senegalensis and Securidaca longepedunculata, formerly used for this need. Also, Piliostigma reticulatum is the main species used in farm lands to combat low soil fertility. Pterocarpus lucens and Adansonia digitata are the main fodder species both during dry and rainy seasons. Apart from the household surveys, vegetation survey was conducted on 96 plots in Sillia. The results showed that 25 species cited in the household surveys had locally disappeared, 22 were rare, 5 were abundant and the others were relatively abundant. Certain collection practices of given species in many use categories increase their vulnerability. Conclusion This study documented preferred species in the adaptation strategies to changing environments and also assessed their vulnerability status under human influence; it is therefore of great use for designing sustainable management