Indo-US AKI Project on Sustainable Water Resources Management Irrigation & Fertilizer Affects on Productivity, Water Use and N Balance in Rice & Maize Cropping Systems in Telangana Region, India Dakshina Murthy Kadiyala ANGR Agricultural University & University of Florida
Advisory committee 1.Dr. Yuncong Li 2.Dr. Rao Mylavarapu 3.Dr. K. Ramesh Reddy 4.Dr. James W. Jones 5.Dr. M. Devender Reddy (ANGRAU)
Background By 2025, 30% of the human population would be threatened by water scarcity 70% of water available is used in irrigated agriculture In Asia, more than 50% of irrigation water is used to irrigate rice
Distribution of rainfall (mm) 800 700 600 500 400 300 SWM NEM 200 100 0 Coastal Telangana Rayalseema AP
Tanks (reservoirs)
Area irrigated by tanks (x 10 3 ha) 1000 900 800 700 600 500 400 300 200 100 0 98-99 99-00 2000-01 2001-02 2002-03
Present status of tanks Unreliable water supply Reduction in storage capacity Cultivation of catchments and foreshore areas Inadequacy in system management Conveyance losses Un scientific usage of water Bad health of irrigation systems Lack of conjunctive use of water Traditional cropping rice is predominant
Present status of tanks (reservoirs)
Review of work Irrigated rice in India typically grown under submerged conditions (5-10 cm depth of water). Most of the water used for rice is lost through percolation, seepage and evaporation and it requires much water than any other field crop New water saving technologies such as: alternate wetting and drying raised bed rice cultivation aerobic rice cultivation were developed.
Review of work Aerobic rice is a new system of rice cultivation for water saving, in this system fields remain unsaturated through out the crop growth and water will be applied to bring the soil water content to field capacity
On average aerobic rice filed used 190 mm less water in land preparation and had 250-300 mm less seepage and percolation. 80 mm less evaporation and 25 mm less transpiration than flooded fields
Nitrogen N is a very crucial and important nutrient required for rice crop growth and yield N use efficacy(nue) in rice very low and various methods were tried to increase NUE but still it is in the range of 30-40%.
N in soil lost mainly through leaching runoff, denitrification and ammonia volatilization In the aerobic rice cultivation soil is kept at near saturation, very little ammonia volatilization can be expected from fertilizer N application
Maize Maize is an important cereal crop grown extensively during dry season in India. It is the most efficient field crop in producing higher dry matter for unit quantity of water. Corn plants are very sensitive to water stress because their root system is relatively sparse. Root system at tasseling showed 85% with in 30 cm of soil
In maize maximum N use efficiency can be obtained with low N rates applied with light and frequent irrigations The maize crop will produce higher yields when fertilizer uptake is enhanced by high soil moisture level
Hypotheses Growing rice aerobically requires less water and losses of N by volatilization and denitrification can be reduced. With changes in the water regime the N transformation in soil and uptake by plants will be altered. Drip irrigation in maize will improve the yield, water use efficiency and better economy of applied N can be achieved
Objectives Develop water saving irrigation methods in rice and maize to improve water productivity Study the effect of irrigation methods and N application rate on grain yield and N uptake and recovery in rice-tomato and maize-rice cropping system. To extend the analysis of N and water management options using crop-soil models to develop optimal N and water management strategies.
Plan of Work Expt. I. Effect of method of rice management and fertilizer levels on yield and water use in rice tomato cropping system
Plan of Work Treatments Main Plots : Systems of rice cultivation 1.Transplanted flooded rice 2.Aerobic rice - irrigation scheduled when soil moisture tension reaches -15 kpa at 15 cm depth
Sub Plots (2) : Fertilizer levels 75% of recommended N (90 kg N/ha) 100% of recommended N (120 kg N/ha)
Aerobic rice concept Grow rice like other cereal: no puddling, no standing water, no soil saturation, dry land preparation
Design : Split plot Replications : Five Plot size : 5.0 m X 4.5 m Season : Wet Season, 2008 Duration : Two years Spacing : 20 x 15 cm Total plots : 2 x 2 x 5 = 20 (P and K and Zn as per recommendation) 15 N studies will be done in 2.0 m x 2.0 m controlled plot in the middle of each treatment
Lay out of rice experiment R1 R2 R3 R4 R5 F1 N1 F1 N2 F1 N1 F1 N2 F1 N1 F1 N2 F1 N1 F1 N2 F1 N1 F1 N2 Irrigation and Buffer channel F2 N1 F2 N2 F2 N1 F2 N2 F2 N1 F2 N2 F2 N1 F2 N2 F2 N1 F2 N2 F1 : Aerobic rice F2 : Flooded rice N1 : 75% recommended Nitrogen N2 : 100% Recommended nitrogen
Expt. II. Effect of method of irrigation and nitrogen levels on the productivity, water balance and N balance in maize (dry) - rice (wet) cropping system
Sub plots :Fertilizer levels 1.75% of recommended N (90 kg N /ha) 2.100% of recommended N (120 kg N/ha) (P and K and Zn as per recommendation)
Design : Split plot Replications : Five Plot size : 6.0 m X 5.0 m Season : Dry season 2008-09 Duration : Two years Spacing : 75 x 20 cm Total plots : 2 x 2 x 5 = 20 N 15 studies will be done in 2.0 m x 2.0 m controlled plot in the middle of each treatment
Wet season, 2009 The rice crop will be grown as per recommendation in each plot and data will be recorded on the residual effects of previous treatments
Lay out of Maize experiment R1 R2 R3 R4 R5 F1 N1 F1 N2 F1 N1 F1 N2 F1 N1 F1 N2 F1 N1 F1 N2 F1 N1 F1 N2 Irrigation and Buffer channel F2 N1 F2 N2 F2 N1 F2 N2 F2 N1 F2 N2 F2 N1 F2 N2 F2 N1 F2 N2 F1 : Furrow irrigation N1 : 75% recommended Nitrogen F2 : Drip irrigation N2 : 100% recommended Nitrogen
Research results & Data to be recorded 1.Weather data maximum and minimum temperature solar radiation Precipitation soil temperature RH (%) Evaporation Wind velocity (km/h)
2. Initial Soil characterization Soil depths: 0-120 cm Bulk density Saturated hydraulic conductivity organic carbon Volumetric water content at saturated, Field capacity & lower limit (PWP) conditions ph, EC, Available N, P & K,
3. Initial conditions Previous crop, root and nodule amount, amount of straw incorporated (kg/ha) with N and P concentration
4. Management data Cultivar name and type Planting date, depth and method Plant population Irrigation depth, timing and method Fertilizer timing, amount and method Pesticide application details Tillage operations Harvest timing
5. Rice parameters Plant height at every 15 days & at harvest LAI and dry matter at every 30 days Days to flowering & physiological maturity Effective tillers/m 2 Number of grains/panicle 1000 grain weight, Grain & straw yield N & P content in grain and straw
6. Maize parameters Plant height at every 15 days & at harvest LAI and dry matter at every 30 days Days to silking & physiological maturity Number of cobs per plant cob length, Cob girth, weight & 100 seed weight Grain yield N & P concentrations in grain and straw
7. Soil nutrients analysis Irrigation and rain water monthly: NH 4, NO 3 Soil monthly: NH 4, NO 3 N isotope studies to quantify different N processes
8. Plant analysis Rice: Plant biomass & NPK at active tillering, panicle initiation & at Harvest Maize: Plant biomass & NPK at knee high stage, silking & at harvest
9. Ground Water Water table depth NH 4, NO 3 & TP 10. Data on residual crop (Tomato and rice) Yield 15 N in plants & soil Water use System NUE System WUE
Acknowledgements Dr. M. Devender Reddy, Principal Scientist (Agronomy) Dr. M. Umadevi, Senior Scientist (Soil Science) Dr. P. Ramulu, Senior Scientist (Agronomy)
Thank you Comments and questions????