Harsimran Kaur

Mitigating future climate change effects by shifting planting dates of crops in rice-wheat cropping system

The present study focuses on (1) impact of climate change scenarios on crop yields in rice–wheat cropping system in central Indian Punjab and (2) assessment of shifting trans-/planting date as an adaptation strategy to mitigate that impact. Climate scenarios were derived from General Circulation Model’s simulations viz. Hadley Center Coupled Model Version 3, Australia’s Commonwealth Scientific and Industrial Research Organization Mk2 and Second Version of Canadian Center for Climate Modeling and Analysis Coupled Global Climate Model. Crop duration and yields were simulated with CropSyst model. Simulation analysis showed decline in crop yields depending upon changed levels of temperature and CO2 in different scenarios. The magnitude of yield decline was highest in 2080 under the A2 scenario of the CCCMA model. Under the changed climate, shifting trans-/planting date from 171st to 178th for rice and from 309th to 324th Julian day for wheat resulted in least reduction in crop yields and surfaced as a practical adaptation measure for sustaining yields in future.

WATER AND NITROGEN-BALANCE AND -USE EFFICIENCY IN A RICE (ORYZA SATIVA)-WHEAT (TRITICUM AESTIVUM) CROPPING SYSTEM AS INFLUENCED BY MANAGEMENT INTERVENTIONS: FIELD AND SIMULATION STUDY

SUMMARY The present study concerns identification of the most profitable and water and nitrogen use efficient best management practice (BMP) in a rice–wheat system using a combined approach of field experimentation and simulation. In the field study, two independent experiments, (1) effect of three transplanting/sowing dates, two cultivars and two irrigation regimes and (2) effect of four nitrogen (N) levels with four irrigation regimes, were conducted for two seasons of 2008–09 and 2009–10 at Punjab Agricultural University, Ludhiana, India. Integrating the treatments of the two independent field experiments, simulations were run with the CropSyst model. The BMP demonstrated was transplanting of rice on 20 June and sowing of wheat on 5 November, irrigation to rice at 4-day drainage period and to wheat at irrigation water depth/Pan–E (open pan evaporation) ratio of 0.9, and fertilizer N of 150 kg ha−1 to each crop for medium-duration varieties. This practice gave higher profit (35%), equivalent rice yield (16%), crop water productivity (15%), irrigation water productivity (51%), economic water productivity (34%) and economic N productivity (94%) than the existing practice by the farmers. The improvement in crop water productivity by shifting the transplanting/sowing date was due to reduction in soil water evaporation and increased transpiration and fertilizer N productivity through increased N uptake.

Effects of substrate hydroponic systems and different N and K ratios on yield and quality of tomato fruit

ABSTRACT The present study was carried out to determine the influence of wick and drip substrate hydroponic systems and different ratios of nitrogen (N) and potassium (K) in the nutrient solution on fruit yield and quality (titratable acidity, total soluble solids, ascorbic acid, total soluble sugars, firmness, lycopene, carotenoids) in tomato. Summer and winter tomato crop was raised under two substrate hydroponic systems. Four nutrient solutions (N:K ratios in four combinations) were tested in both the growing seasons at vegetative and reproductive stages of plant development. Among the different nutrient solutions, the solution containing N and K in the ratio of 1.4:3 at vegetative and 1.7:3.5 at reproductive stage increased the total fruit yield and quality of tomato irrespective of hydroponic system or season. Among the hydroponic systems, wick system produced higher fruit yield and better quality in terms of firmness, ascorbic acid, and total soluble sugars in winter crop.