Optimum time of sowing for rainfed winter chickpea with one-pass mechanised row-sowing: an example for small-holder farms in north-west Bangladesh

Abstract

The time of sowing chickpea (Cicer arietinum L.) in the High Barind Tract of north-west Bangladesh is critical to crop success. To ensure adequate emergence and subsequent crop growth, chickpea relies on residual soil moisture stored in the profile after rice (Oryza sativa L.) cultivated in the preceding rainy season. With the development of mechanised, one-pass minimum tillage sowing, the time between rice harvest and chickpea sowing is decreased, and temperature constraints that limit biomass and/or pod formation and filling may be avoided. Minimum tillage may also limit evaporation from the soil surface compared with traditional, full cultivation procedures. The objective of this study was to identify the optimum sowing time to achieve adequate crop establishment and limit exposure of the chickpea crop to terminal drought and heat stress later in the growing season. Over three experimental seasons, chickpea sowing dates were spread from 22 November to 22 December. Soil water content, crop growth and temperature were monitored to determine the optimum sowing time. Over all seasons and sowing dates, the volumetric soil water content in the seedbed under minimum tillage remained within 17–34%, a range non-limiting for chickpea establishment in glasshouse and field experiments. Late planting (after 10 December) exposed seedlings to low temperatures (<15°C), which limited biomass formation and extended the vegetative growth phase into periods with high maximum temperatures (>35°C), resulting in unfilled pods and depressed grain yield. The preferred sowing time was determined to be 30 November to 10 December to reduce the risk of high temperatures and low soil water content during chickpea reproductive growth causing terminal heat and drought stress, respectively. Mechanised sowing in one operation allows farmers to optimise their time of sowing to match seed requirements for soil water at emergence and may assist farmers to avoid temperature stresses (both low and high) that constrain chickpea vegetative and reproductive growth.

Conservation Agriculture for Rice-Based Intensive Cropping by Smallholders in the Eastern Gangetic Plain

“…Research and development in Bangladesh have developed effective CA practices for smallholder farms in the EGP using minimum soil disturbing implements mounted on 2WTs. The key outcomes are new knowledge developed on: (i) effective strip planting using the VMP [4][5][6]; (ii) planting machinery development and performance testing in the small fields using 2WTs [4,9]; (iii) agronomy for mechanised seeding with minimum soil disturbance and residue retention [5,6]; (iv) weed dynamics and weed management under CA [11][12][13][14][15][16]33]; (v) crop rotation effects on soils and weeds [33,34]; (vi) mechanised transplanting of NPT rice [24,25]; (vii) soil improvement under CA [17][18][19][20][21][22]; (viii) decreased greenhouse gas emissions under CA [23]; (ix) increased profit from CA-based SP + NPT rice in farmers' fields [8]; (x) water balance [27], which showed that wheat under CA (SP and increased residue retained) required 11-33% less irrigation water than the convention practices; and (xi) commercialisation models for sales of planters to LSP [31]. Based on the evidence presented, there should now be sufficient confidence for more widespread demonstrations across different agro-ecosystems in the EIP and for programmes to engage the private sector and farmers in adoption and out-scaling of CA for smallholder rice-based crop production in the EGP.…”

“…The nation-wide spread of mechanized tillage with two-wheel tractors (2WT), and development over the past decade of a range of minimum soil disturbance planters for 2WT, provide a platform for implementing CA principles that will decrease costs of crop production (less fuel consumption and decreased labour requirements) and improve the fertility of soils in Bangladesh. Evaluation of the Versatile Multi-crop Planter (VMP) [4][5][6] showed promising results for the establishment and yield of a range of crops in rainfed cropping systems. This novel, lightweight, low-cost planter is now being manufactured in Bangladesh.…”

Optimum Soil Water Content for Chickpea Emergence in Heavy‐Textured Soils of North‐West Bangladesh

“…In a parallel field study in the HBT by Vance et al (2014), it was found that within the range of sowing dates from 22 November to 22 December, h g remained between 12 % and 24 % (w/w). The seeds were sown in one pass using mechanised row-sowing.…”

Breeding for Abiotic Stress Adaptation in Chickpea (Cicer arietinum L.): A Comprehensive Review

“…The critical period to determine chickpea yield is extended due to its indeterminate nature but is centred around flowering, with seed number which is related to both pod number and seeds per pod accounting for most of the variation [28]. Heat stress decreases grain yield through increasing the proportion of unfilled pods and decreasing the duration of the reproductive growth stage [50]. the consequent impact of reduced sucrose content in the leaves and anthers [31,51].…”

“…Sowing chickpea at low temperatures delays emergence due to the longer time to accumulate the required minimum threshold of approximately 115 growing degree days, and subsequent low temperature or frost events decrease the rate of plant growth eventually lengthening the duration of the vegetative growth stage and delaying flowering, podding and maturity [36,37,40,50]. Depending on the production region, this resultant long season can expose the plants to later season rainfall, thus potentially increasing yield.…”