Yields and qualities of pigeonpea varieties grown under smallholder farmers’ conditions in Eastern and Southern Africa

Pigeonpea is one of the few crops with a high potential for resource-poor farmers due to its complementary resource use when intercropped with maize. A three year comprehensive comparative study on the performance of six pigeonpea (Cajanus cajan) varieties on farmers’ fields in Eastern and Southern Africa where intercropping with maize is normal practice, was undertaken. The varieties were tested for accumulation of dry matter (DM), nitrogen (N) and phosphorus (P) in all above-ground organs for three years under farmers’ conditions. The study revealed that the latest introduced ICEAP 00040 outperformed all the other tested varieties (ICP 9145; ICEAP 00020, ICEAP 00053, ICEAP 00068, and a local variety called “Babati White”) under farmer-managed conditions. The harvest indices (HI), ranging from 0.08-0.15 on dry matter (DM) basis, were relatively low and unaffected (P>0.05) by the environmental variation. The N harvest index (NHI) was 0.28 and P harvest index (PHI) was 0.19. The better responses of ICEAP00040 to favourable conditions could however only be realised in a minority of cases as yields generally were low. These low yields are still a major challenge in African smallholder agriculture as pulses play an important role in soil fertility maintenance as well as in the household diets

Advantages of bi-cropping field beans (Vicia faba) and wheat (Triticum aestivum) on cereal forage yield and quality

In organic production systems, penalties in cereal forage yield and low crude protein (CP) concentration are mainly caused by limited soil nitrogen (N) availability, which can be addressed by using cereal/grain legume bi-cropping systems. To confirm this, a bi-cropping experiment of spring wheat cv. Paragon and faba beans cvs. Fuego and Maris Bead was conducted in two years, using a randomised complete block design and sowing the crops in a replacement design series. In 2016, the wheat forage yield in sole cropping exceeded that in bi-cropping by 58%. In 2015, the wheat forage harvest index (HI) in bi-cropping was 14% higher than that in sole cropping, but in 2016 it was 7% lower. In both years, bi-cropping increased the CP and the grain N uptake in the wheat compared with that sole cropping, by 25% and 17%, respectively. The chlorophyll concentration index (CCI) in the wheat was 2.2 times higher in bi-cropping than in sole cropping and 34% higher in the alternate rows systems than in the broadcast system. In 2015, the efficiency of N use (NLER) in bi-cropping was 50.7% higher than that in sole cropping. Alternate row bi-cropping improved NLER over broadcast by 37.9%. Faba bean rust disease was more severe in Fuego than in Maris Bead. In conclusion, bi-cropping in uniform alternate row spacing can improve productivity and nutritional quality of wheat forage, compared with sole cropping. The bi-crop bean cultivars Fuego and Maris Bead can, improve wheat straw CP and reduce rust disease severity, respectively

The effect of bi-cropping wheat (Triticum aestivum) and beans (Vicia faba) on forage yield and weed competition

Field experiments were conducted from April 2015 to September 2016 at the Royal Agricultural University, UK to explore the impact of drilling pattern and species mixtures on weed growth and forage yield. The bi-crops of spring field bean (Vicia faba) cv. Maris Bead and Fuego with spring wheat (Triticum aestivum) cv. Paragon were evaluated at four drilling patterns in a randomized complete block design with four replicates and compared against their respective sole crops. Weed DM was 59% higher in sole cropping systems than bi-cropping systems. Sole cropping systems outperformed bi-cropping systems for wheat (in 2016 only) and bean forage DM yield. However bi-cropping systems produced higher total forage DM yield than sole cropping systems. Weed DM was higher in broadcast than alternate rows. Bean forage DM was higher in alternate rows than broadcast by 74%. Wheat forage DM was not affected by the drilling patterns. Maris Bead had higher forage DM than Fuego (in 2016 only). In conclusion, bi-cropping can increase land productivity per unit area over sole cropping whilst improving forage DM yield and providing low cost integrated weed management. Alternate row drilling can improve bi-cropping productivity over broadcast practice

Multiple nutrient imbalances in eara-leaves of on-farm cultivated maize in Eastern Africa

Maize is a major food crop in eastern and southern Africa and is often cultivated with insufficient supplies of nutrients. The current studies are aimed at diagnosing any potential nutrient limitation in maize under farmers’ conditions using the nutrient content in ear leaf tissue at tasseling stage. The majority of the maize crops were considered below the critical nitrogen (N) content in the ear leaves with mean N content of 1.84%. Phosphorus (P), B and Cu content appeared critically low at three of the four sites. Unique fingerprinting by multivariate statistics was possible for each site when using the proportion of nutrients in the leaf tissue. The content of six macro elements (N, P, K, S, Mg, Ca) at the tasseling stage were found to be able to predict 83% of the variation in the grain yield at maturity whereas the inclusion of micronutrients only improved this prediction with an additional 3%. N alone predicted 50% of the variation in grain yield and the N supply of the maize crops in eastern and southern Africa must thus be the first priority before yields can be improved

Model validation through long-term promising sustainable maize/pigeon pea residue management in Malawi

In the 2005/2006 season, the Model Validation Through Long-Term Promising Sustainable Maize/Pigeon Pea Residue Management experiment was in the 11th year at Chitedze and Chitala, and in the 8th year at Makoka and Zombwe. The experiment was a split-plot design with cropping system as the main plot and residue management as the subplot. All treatments were subjected to two fertilizer regimes. In the first regime, there was no addition of inorganic fertilizer and in the second, there was addition of inorganic fertilizer at area-specific fertilizer recommendation rate. The evaluation was done at Chitala, Chitedze, Makoka and Zombwe. Significant differences (P = 0.05) were observed in maize grain yield among sites and cropping systems. Highest grain yields were recorded at Chitedze (5,342 kg/ha). However, the response trend in grain yield to different cropping systems remained the same in all sites. Best yields were recorded in maize grown following pigeon pea in rotation system followed by maize intercropped with pigeon pea. The addition of inorganic fertilizer increased maize yield significantly. Removal or retention of crop residue in the field did not contribute any significant yield increase of maize across sites. For resource-poor smallholder farmers, growing maize/pigeon pea in rotation and maize intercropped with pigeon pea seems to be more profitable in terms of resource utilization and soil fertility improvement

Yields and accumulations of N and P in farmer-managed intercrops of maize-pigeonpea in semi-arid Africa

Maize (Zea mays L.) is a major staple food in Sub-Saharan Africa but low soil fertility, limited resources and droughts keep yields low. Cultivation of maize intercropped with pigeonpea (Cajanus cajan L. Millsp.) is common in some areas of eastern and southern Africa. The objectives of this study were (1) to investigate dry matter, nitrogen (N) and phosphorus (P) accumulation in different plant components of maize-pigeonpea intercropping systems and (2) to report the effects of the intercrops on soil fertility. Maize-pigeonpea intercrops were compared to sole maize grown using farmers’ practices. Intercropping maize and pigeonpea increased (P0.11). Nitrate and ammonium levels in soil were still not affected by the treatments after the soils were incubated in anaerobic conditions for 8 days at 37ºC (P>0.11). However, pigeonpea added up to 60 kg of N ha-1 to the system and accumulated up to 6 kg of P ha-1 and only 25% of this N and P were exported in the grain. In conclusion, beside the added grain yield of pigeonpea in the intercropped systems, pigeonpea increased the recirculation of dry matter, N and P which may have a long-term effect on soil fertility. Furthermore, the stems from pigeonpea contributed to household fuel wood consumption. The intercropped system thus had multiple benefits that gave significant increase in combined yield per unit area without additional labour requirements. The main requirement in order to up-scale the maize-pigeonpea intercropping approach is sufficient supply of high-quality pigeonpea seeds