180 m. ha is under Vertisols globally Distributed across Northern Australia, India, Ethiopia, Sudan, Argentina, Mexico and Central America. 72.9 m. ha is in India, that is 22.2% of India’s geographical area. Distributed in the states of Maharashtra (84%), Gujarath (48%), Madhya Pradesh(38%) Andhra Pradesh (26%).
Vertisols are difficult to Manage as they shrink and crack, becomes hard on drying. Swell and sticky with rains. Twin problems : poor drainage – water logging due to high clay content (40-60%, up to 80%). Farmers keep Vertisols fallow in rainy season, and sow crops in Sept-Oct on stored soil moisture. Rainy season fallow Vertisols distribution States Rainy season fallows (m. ha)All India 26.2Madhya Pradesh 5.378Maharashtra 4.642Andhra Pradesh 2.253
Water balance studies for 6 years on rainy season fallows showed rainfall losses are :Waterlogging on Vertisols during rainy season 25% as runoff against 15% as runoff from cropped fields. 25% of rainfall lost through evaporation. 9% of rainfall lost in deep percolation 41% of rainfall is potentially available for post rainy season crops. Runoff and soil erosion from Vertisols 10-43 t ha-1 yr-1 of soil is lost through soil erosion from fallows. 80% of soil erosion could be reduced with cropping .
Chickpea after a rainy season fallow (FCP-FCP) Farmers’ risk management strategy is to leave the land fallow during rainy season. Sow crops like sorghum, chickpea, safflower year after year on these Vertisols. Sorghum after a rainy season fallow (FS-FS) Farmers preferably sow post rainy season crops in the month of October based on receding monsoon rainfall. Generally farmers sow traditional varieties.
monthly mean rainfall (mm) Pan Evaporation 400Mean monthly rainfall and 350 Rainy season evaporation (mm) 300 250 200 Post-rainy season 150 100 50 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Rainfall ranges from 750-1250 mm on Vertisols regions in India, Rainy season cropping period is June- September, ET is less than rainfall from July to September months
Our main goal was to enhance sustainableproductivity, and specific objectives are:1. Identify improved sustainable cropping system options for enhanced crop productivity.2. Quantify the benefits of grain legumes in the intensified cropping system rotations.
Experiment was conducted for 15 years at ICRISAT farmfrom 1983 to 1997 seasons.Main plots: cropping systems 1st Year 2nd Year Rotation Abbreviation Rainy Post-rainy Rainy Post-rainyMung bean (M) + Sorghum Mung bean + Sorghum MS-MSSorghum (S) + Chickpea (CP) Sorghum + Chickpea SCP-SCPFallow (F) + Sorghum(S) Fallow + Sorghum FS-FSFallow + Sorghum Fallow + Chickpea FS-FCPSub plots: Nitrogen application 4 levels of Nitrogen 0, 40, 80,120 kg ha-1 for cereals only (sorghum). Rainfed cropping completely and no irrigation for crops.
Mung bean in rainy season Mung bean was dry seeded during first fortnight of June before monsoon rains. 270,000 plants ha-1 population was maintained for mung bean. Sorghum in post-rainy season Post-rainy sorghum sown in the 3rd week of September after mung bean harvest. 120,000 plants ha-1 was maintained for post-rainy sorghum.
Rainy season sorghum Rainy sorghum was dry sown, to maintain 180,000 plants ha-1 . Cultivar sown was CSH-6 in all the years. Chickpea sown after the harvest of sorghum Chickpea cultivar Annegiri was sown one week after harvest of sorghum without any cultivation. 333,000 plants ha-1 was maintained
Fallow+sorghum (F+S) Fallow+chickpea (F+CP) Sorghum cultivar CSH-8R was sown after fallow in Sep-Oct in FS-FS treatment. Post rainy sorghum was maintained at 120,000 plants ha-1. Chickpea sown after rainy season fallow in Sep-Oct in FCP treatment. Population target was 333,000 plant ha-1.
12000Grain yield (kg ha-1 two-year rotation-1) chickpea sorghum mung bean 10000 8000 6000 4000 2000 0 N-40 N-80 N-40 N-80 N-40 N-80 N-40 N-80 N-0 N-0 N-0 N-0 N-120 N-120 N-120 N-120 FS-FS MS-MS FS-FCP SCP-SCP Cropping systems Error bars (SE±) indicate standard error for each crop yield
mungbean sorghum chickpea Crop mean uptake of N (kg ha-1 two-year 250 200 150 rotation-1) 100 50 0 N-0 N-0 N-0 N-0 N-120 N-120 N-120 N-120 N-40 N-80 N-40 N-80 N-40 N-80 N-40 N-80 FS-FS MS-MS FS-FCP Cropping systems SCP-SCPError bars indicate SE± for the crops mean uptake in two-year rotation
Mean water use efficiency (WUE) for crops and rotationCropping Crops Systems of two-year rotationsystem WUE (kg ha-1 mm-1) N0 N 40 N 80 N120SCP-SCP Rainy sorghum 11.4 18.6 21.8 23.2 chickpeaMS-MS Mung bean 9 12 13.8 14 PR. sorghumFS-FS PR. sorghum 4.4 8.6 10.2 11.8FCP-FS Chickpea- 5.6 7.5 9.3 9.4 PR. sorghum
120000Gross returns (Rs. ha-1 two- N-0 100000 Gross returns increased in N-0 year rotation-1) with MS-MS exceeded by Rs 80000 22,000 and with SCP-SCP 60000 exceeded by Rs. 30,000 in two- 40000 year rotation. 20000 0 FS-FS MS-MS FS-FCP SCP-SCP 120000 mungbean sorghum Gross returns (Rs. ha-1 rotation 100000 sorghum fodder chickpea N-80 80000 Gross returns increased in N-80 with MS-MS exceeded by Rs cycle-1) 60000 30,000 and with SCP-SCP by Rs. 40000 34,000 in two-year rotation. 20000 0 FS-FS MS-MS FS-FCP SCP-SCP Cropping systems
Double cropping with MS-MS or SCP-SCP replacing fallows improves WUE between 19%-165% at same N level across systems. Farmers’ gross returns increase by Rs.22000-25000 ha-1 two-year rotation-1 at N-0 over traditional fallow systems. Yield response to applied Nitrogen increased by 2-3 fold in rainy season crops as well as post-rainy crops in the systems. Post-rainy season cereal or legume that follows a cereal in rainy season require N application to utilize water more efficiently . Adopting opportune double cropping on dryland Vertisols enhances productivity and additional N uptake of 30 kg N ha-1 y-1 by crops in N-0 for 15 years.