Testing pearl millet and cowpea intercropping systems under high temperatures

Abstract

With the potential threat of more frequent climate extremes putting semi-arid crop production in jeopardy, there is a need to establish more climate resilient cropping practices. Intercropping is often practiced by farmers in semi-arid regions and is perceived as a risk reducing practice. However, there is little knowledge of how and to what extent it can be a viable option under future conditions. As testing a complex adaptation strategy in controlled environments is difficult, conducting field experiments in the dry season offers opportunities to test cropping systems under extreme but real-world conditions. Consequently, a field trial was run in semi-arid India over a two-year period (2015 and 2016) in the dry and hot (summer) season. These trials were set up as a splitsplit-plot experiment with four replicates to assess the performance of simultaneously sown sole versus intercropped stands of pearl millet and cowpea, with two densities (30 cm and 60 cm spacing between rows-both with 10 cm spacing within rows), and three water treatments (severe stress, partial stress, and well-watered) applied with drip irrigation. Results showed that intercropping pearl millet led to a significantly lower total grain yield in comparison to the sole equivalent. Pearl millet's highest yields were 1350 kg ha −1 when intercropped and 2970 kg ha −1 when grown as a sole crop; for cowpea, 990 kg ha −1 when intercropped, and 1150 kg ha −1 as a sole crop. Interestingly, even when maximum daily temperatures reached up to 42.2°C (on Julian day 112 in 2016), well-watered, pearl millet produced reasonable yields. Cowpea yields were often lower than 1000 kg ha −1. Only under the highest irrigation treatment (well-watered) sole cropped, low density were yields of 1150 and 1110 kg ha −1 achieved in 2015 and 2016, respectively. We conclude that successful intercropping systems must be highly specific to conditions and demands. More research would be needed to identify suitable cowpea genotypes and planting densities that could allow for higher intercropped pearl millet yields. Recent studies have highlighted areas of India that have become

Productivity and profitability of maize-legume cropping systems under conservation agriculture among smallholder farmers in Malawi

“…The differences in pLER between CA and CT when maize was intercropped with cowpea could be explained in terms of efficient utilisation of water resources in intercrop systems. Similar results have been reported by (Chimonyo et al 2018;Nelson et al 2018) who demonstrated reduced competition for water resources between cereals and cowpea grown in intercrops. Pigeon pea shows slow growth in the initial stages of plant growth and takes over after maize has matured, thus offering little competition to maize (Sakala et al 2000).…”

Uptake of Climate-Smart Agricultural Technologies and Practices: Actual and Potential Adoption Rates in the Climate-Smart Village Site of Mali

“…The high adoption rate of these practices can be attributed to the fact that crop yield increases with the adoption of intercropping, micro dosing and FMNR practices which in long run can better contribute to food security [6,34,35]. In semi-arid crop production where there is a potential treat of more frequent climate extremes, intercropping is an important crop production strategy for smallholder farmers for productivity improvements per unit of land [36]. Previous studies reveal that intercrop systems provide benefits such as complementary use of resource niches in term of the different rooting behavior of crops [37] and better system protection again pests and diseases [38].…”

Practices for the improvement of the agricultural resilience of the forage production in semiarid environment: a review

“…However, it must be taken into consideration that competition between plants for natural resources such as water, light and nutrients in an intercropped system is inevitable, and this leads to distinct yields between monocultures and intercropping (Sadeghpour et al, 2013). Nelson et al (2018) found that intercropping with cowpea significantly decreased millet yield in a semi-arid region of India; however, millet was tolerant to the region's high temperatures and water restriction in treatments with poor irrigation.…”

“…It is a plant that possesses the Crassulacean Acid Metabolism (CAM), with high water storage capacity and high efficiency in its utilization, besides being rich in energy and minerals (Scalisi et al, 2016). Despite the forage cactus present several qualities, it is a culture poor in fiber (Ben Salem and Smith, 2008), this characteristic is observed among other cultures as in the millet (Pennisetum glaucum) which, in turn, also appears as a good alternative to boost the production of forage, since it is a species of metabolism C4, averagely tolerable to salinity, as well as the hydric stress and to the high temperatures (Nelson et al, 2018), common features in the arid and semiarid regions. It also possesses good biomass production and nutritive value (Santos et al, 2017a).…”