Simulation Scenarios of Baseline Management

We could simulate yield estimate of rainy season sorghum and sequential chickpea system in hindcast for all years as well as ENSO phase forecast considering analog years, with sowing opportunity triggered between 15 and 25 June, when 5 days accumulated rainfall exceeded 60 mm or extractable soil water was greater than 65 mm in the wet sowing zone of the soil for Kurnool region. Farmers usually apply two bags of fertilizer per acre in different N-P-K grades (18-46-0, 20-20-0, 17-17-17, 28-28-0), giving a nutrient application (kg ha-1) ranging from 42.5-70 N, 42.5-115 P2O5 and 42.5 K2O. However, in simulations, we considered application of 80 kg N ha-1 during La Niña and 40 kg N ha-1 during El Niño and ENSO neutral for both the crop seasons as the optimal practice compared to baseline simulation of single crop kharif sorghum with 40 kg N ha-1 application for all year.

In Anantapur, a sole crop peanut is traditionally grown by risk-averse farmers which is sown any time, but mostly from the 3rd week of July to 2nd week of August, with a fertilizer application at 20 kg N ha-1 and this was considered as a baseline management simulation. We simulated peanut/medium duration pigeonpea cropping system with sowing triggered between 25 June and 21 July, and planting at a wide row ratio of 7:1 as the optimal management during the La Niña seasons. Peanut/medium duration pigeonpea intercrop was generally recommended for farmers to suit longer cropping season, and ICRISAT promoted peanut/short duration pigeonpea intercrop system as suitable for short seasons after carrying out systems analysis for Anantapur. During El Niño and ENSO neutral years, sowing opportunities were triggered between 15 July and 15 August with peanut/short duration pigeonpea intercrop system, at 3:1 to 7:1 row ratios under Anantapur conditions. Simulations were carried out with these intercrop systems using 40 kg N ha-1 application using observed weather for the ENSO phase analog years.

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