Soumya drought and its mitigation

Drought and its mitigation strategies in agriculture

1. Drought and its mitigation strategies in agriculture SEMINAR on COLLEGE OF AGRICULTURE, DEPARTMENT OF AGRONOMY PRESENTED BY: Soumya Ranjan Bhuyan I.D No.-160111022 MAJOR ADVISOR Dr. Manish Bhan Asst. Professor Agronomy SEMINAR INCHARGE Dr.M.L Kewat Professor,Agronomy

2. Sequence of presentation Introduction Concept of drought Mitigation techniques Mitigation through crop management practices Soil and water conservation techniques Conclusion

3. INTRODUCTION INTRODUCTION

4. Source-NICRA,2014

5. Some news…..

6. Drought is a situation when the actual seasonal rainfall is deficient by more than twice the mean deviation (Ramdas,1960) Drought is defined by deviation from the normal rainfall, it can happen in all rainfall regions. It also occurs in high rainfall area but severity or frequency may vary. Drought is considered to be a strictly meteorological phenomenon. It is also a complex phenomenon whose severity depends on the precipitation amount, its time and space distribution, evapo-transpiration and on hydrological factors . Definition

7. Classification of drought Meteorological drought: It is defined as a situation when there is a 25% decrease in average rainfall for a given period of time( IMD,Pune ) Hydrological drought: Depletion of surface water and consequently drying of reservoirs, tanks etc. It results in deficiency of water for all sectors using water. Agricultural drought: It is the result of soil moisture stress due to imbalance between available soil moisture and evapotranspiration demand of a crop. Socio-economic drought: This is associated with the supply & demand of some economic goods. This drought should be linked hot only to precipitation but also trends of fluctuations in demand.

8. Classification of drought Meteorological drought Hydrological drought Agricultural drought

9. Shortage of water Desertification Death of livestock Lack of water for irrigation Reduced crop yield Migration of people Scarcity of seed Consequence of drought

10. Effects of drought on plants Loss of turgidity Photosynthesis Increase in number of stomata ABA accumulation Rolling and wilting of leaves Reduced tillering Forced maturity Reduction in productivity

11. Table 1: Economic yield reduction by drought stress in some representative field crops Crop Growth stage Yield reduction Barley Seed filling 49 – 57% Maize Grain filling 79 – 81% Maize Reproductive 63 – 87% Maize Vegetative 25 – 60% Rice Reproductive (severe stress) 53 – 92% Dryland farming - Crops and Techniques for Arid Regions -R. Crosswell and F.W. Martin

12. Drought stress resistance mechanism in plants Plants optimize the morphology, physiology and metabolism of their organs and cells. The reactions of the plants to water stress differs significantly at various organizational levels depending upon intensity and duration of stress as well as plant species and its stage of development

13. Adaptations Drought escape Drought resi stance Drought tolerance Drought avoidance Water conservation More water uptake Mitigating drought High tolerance to drought Principles of agronomy Yellamanda Reddy and Shankara Reddy

14. Stress avoidance : is the ability of plant to maintain high tissue water potential under drought conditions. Stress tolerance : is a plant’s stability to maintain its normal functions even at low tissue water potentials. Stress r esistance Stress tolerance Stress avoidance

15. Stress avoidance is usually achieved through morphological changes in the plant : Reduced stomatal conductance Decreased leaf area Development of extensive root systems Increased root/shoot ratios Stress tolerance is achieved by mitigating stress and high degree of tolerance by plants.

16. Mitigation strategies Mitigation of Stress by Crop Management Soil and moisture conservation measures

17. Mitigation by crop management practices Selection of crops/varieties Seed hardening Sowing of crops

18. Selection of crops/varieties Short duration Early vigour Deep root system Dwarf plant with erect leaves and stems Moderate tillering Lesser period between flowering and maturity Moderate dormancy Wider adoptability Source-Venketeshwarlu,2009.Indian Journal of Agricultural Science

19. Relative drought tolerant crops RABI KHARIF LEGUMES Oats Barley Triticale Sorghum Pearl millet Kodo millet Green gram Black gram Niger Soybean Groundnut Chickpea Cowpea Pigeon pea

20. Pearl millet : CZIC 923,HHB 67,HHB 68,GHB 183, GHB 1399,etc Cluster bean: Maru guar, FS 277,HG 75, HG 182,I-IGS 365,RGC 936, PLG119, PLG 85, Suvidha , Navcen,etc Mung bean: Asha,K 851,RMG 131,etc Moth bean : RMO 40,Marp moth,Jadia , Jawala,PCMO 880,T 88, CAZRI moth- l,etc . Relatively drought tolerant crop varieties Source-CAZRI,2000 .Strategy to combat drought and famine in the I ndian arid zone

21. Seed hardening Seed hardening: Seed hardening refers to the technique of subjecting seeds to soaking in water or appropriate chemical solutions and drying in shade. It helps the plant to survive during initial moisture stress conditions.

22. Treatments Seed yield ( g plant -1) 100 seed weight ( g) Harvest index ( %) Seed yield ( q ha -1 ) T1 : Control 9.12 26.64 41.1 19.04 T2 : Water soaking 11.11 28.69 42.0 19.41 T3 : CaC12 (1%) 11.58 29.22 47.1 19.12 T4 : CaC12 (2%) 19.15 30.77 53.1 26.32 T5: KH2PO4 (1%) 13.48 26.66 44.0 22.02 T6:KNO3 (100 ppm) 13.77 30.33 43.6 23.73 T7:KCI (100 ppm) 12.85 24.89 46.2 20.65 T8: Sodium molybdate (100 ppm) 12.63 24.52 48.6 21.71 T9: Zinc sulphate (100 ppm) 13.2 26.32 48.7 22.34 T10 : Cycocel (1000 ppm) 16.10 27.70 49.2 23.54 T11:Succinic acid (20 ppm) 14.67 27.20 47.5 23.44 T12: Ascorbic acid (20 ppm) 12.96 26.63 46.6 22.45 S E 0.62 0.73 2.05 1.16 CD at (5%) 1.81 2.11 5.95 3.38 Table 2 : Influence of seed hardening chemicals on yield and yield traits in chickpea. Dharwad Manjunath (2010)

23. Management at sowing Time of sowing An increasing in yield has been found by advancing the date of sowing of kharif and rabi crops. Advantages Better moisture availability Good seedling vigour Longer growing season

24. soil and water conservation method

25. Soil and water conservation methods In-situ moisture conservation practices Water harvesting structures Mulching Anti- transpirants Adopting modern irrigation techniques

26. In-situ moisture conservation practices Land shaping (if the soil depth permits), contour cultivation, field/contour bunding , tie ridging , digging of trenches, ridges and furrow system of sowing, raised on sunken beds are important practices for conserving and managing rain water for realising higher productivity. Compartmental bunding Conservation furrow Broad bed and furrow Ridges and furrow Contour bunding Graded bunding Dead furrow Inter plot rainwater harvesting

27. Performance of chickpea varieties as influenced by compartmental bunding at farmers fields Bellary Patil et al .,(2015)

28. TREATMENTS 30 DAS 60 DAS 90 DAS 120 DAS 150 DAS AT HARVEST Broad Bed and Furrow (BBF) 30.67 28.01 30.19 26.72 21.96 13.80 Farmer Practice (Flat bed-FB) 23.59 24.92 25.44 23.82 19.16 11.94 S.Em+ 0.98 0.07 0.13 0.19 0.09 0.22 CD (P=0.05) 5.94 0.45 0.80 1.13 0.55 1.36 Table 6 : Soil moisture content (%) as influenced in- situ moisture conservation practices at 45-60 cm soil depth Alisaheb et al ,(2015)

29. Water harvesting structures Water harvesting is the process of collecting rainfall and/or runoff from a larger catchments area to be used in a smaller target area ( Oweis et. al., 1999). The collected runoff water may be either directly applied to an adjacent field as supplemental life saving irrigation of crops during moisture stress condition. Some of the water harvesting structures are: Cisterns/ tankas / kund Khadin Village ponds ( Nadis / tobas ) Series of check dams on natural streams Percolation tanks

30. Cisterns/ tankas / kund Underground storage cisterns/ tanka / kund is the most common rainwater harvesting system in the Indian arid zone.Tanka is constructed by digging a circular hole of 3.00 to 4.25 m diameters and plastering the base and sides with 6-mm thick lime mortar or 3mm thick cement. Khadin : Khadin system of water harvesting and moisture conservation is well suited in deep soil plots surrounded by some sort of natural catchment zone. Even during severe drought years, khadins may be used for getting a successful crop on stored soil profile moisture.

31. Village ponds ( Nadis / tobas ): Nadis / tobas are small to medium sized excavated or embanked village ponds, for harvesting precipitation . These ponds can provide water for life saving irrrigation to crop during drought stress . Check dams : In this system the artificial recharge is made to restrict the surface run off through streams and by making additional water available for percolation. Percolation tanks : Percolation tanks are generally constructed on the small streams or rivulets with adequate catchment for impounding surface runoff. These tanks are used entirely for recharging the aquifer through percolation

32. MULCHING Any material used (spread) at surface or vertically in soil to assist soil and water conservation and soil productivity is called much. And process of applying mulches to soil is known as mulching. Mulching helps in conserving moisture, lowering soil temperatures around plant roots, reducing weed growth, etc thus helps crops during moisture stress conditions.

33. Types of mulches 1.Plastic films: They help in maintaining higher water content in soil resulted from reduced evaporation, induced infiltration, reduced transpiration from weeds or combination of all these factors. Examples-Polythene , polyvinyl,etc . 2.Crop residues or stubble mulch: Crop residues and other plant waste products corn , and sawdust) are widely used as mulch. These materials are cheep and often readily available. The permit water to enter in the soil easily, when maintain at adequate level. These materials result in increased water content and reduced evaporation. Examples- Straw , cloves, leaves,etc .

34. 3.Saw dust mulch: Mulching with sawdust is a common practice. Sawdust is acidic, making it a good mulch choice for acid-loving plants.They have high water absorption capacity. 4.Soil or Dust mulch: If the surface of the soil is loosened, it acts as mulch for reducing evaporation. This loose surface of soil is called soil mulch or dust mulch. Inter-culturing creates soil mulch in growing crops and helps in closing deep cracks in Vertisols . 5.Vertical mulch : Vertical mulch is a technique which consists of digging suitable trenches across the slope and thus making more surface are a available for water absorption. Fig. Vertical mulching Fig. Saw dust mulching

35. EFFECTS OF STRAW MULCH ON MAIZE AND WHEAT

36. ANTI-TRANSPIRANTS Anti- transpirants are the materials or chemicals that applied to transpiring plant surfaces for reducing water loss from the plant. The purpose of ATs is to maintain the growth and productivity under stress conditions and it is never recommended for high productivity / unit area. The severity of intermittent drought of 6-10 days during critical stages of the crop can reasonably be avoided by the use of antitranspirants and thus crops can be save Mainly four types of anti- transpirants : Stomatal closing type Film forming type Reflectance type Growth retardant

37. Stomatal closing type: Most of the transpiration occur through the stomata on the leaf surface. They induce stomatal closing or decrease size and number of stomata which subsequently reduce the photosynthesis. Examples: Phenyl Mercuric Acetate (PMA ) Atrazine Film forming type: Plastic and waxy material which form a thin colourless film over the leaf surface and result in a physical barrier. These glossy films then reduce water loss on plants while at the same time allow them to breathe normally. Examples: Hexadecanol (Higher alcohols) Cetyl alcohol Methanol Paclobutrazol Brassinolide Resorcinol

38. Reflecting type: They are white materials which form a coating on the leaves and increase the leaf reflectance (albedo). By reflecting the radiation, vapour pressure gradient and thus reduce transpiration. Examples: Kaoline(5%) China Clay Calcium bicarbonate Lime water Growth retardant: These chemicals reduce shoot growth and increase root growth and thus enable the plants to resist drought. They may also induce stomatal closure . Examples: cycocel

39. Modern irrigation techniques Sprinkler and drip irrigation methods are most suitable moisture stress conditions. These methods help in water conservation. The conveyance losses of water are practically negligible, and risk of soil erosion is low as the application rate is low. Sprinkler system is most suitable for narrow-spacing crops grown on undulating light textured soils. The drip irrigation system is not affected by high wind velocity as it applies water directly in the root zone. This method of irrigation is more suitable for wider spacing crops and orchards. As the irrigation is given directly near the root zone in drip system and whole soil surface is not wetted . wasteful loss of water is minimized .

40. Contingency crop planning Late onset of monsoon : Transplanting Alternate crops/varieties Dry spells during crop periods : Ratooning and thinning Mulching Spraying of urea(2%) Weed control Water harvesting and life saving irrigation Early withdrawal of monsoon : Harvesting at physiological maturity Short duration varieties Strategies adopted for mitigating dry spells during crop periods can be done S.R Reddy, Principles of Agronomy

41. SOME OTHER LONG TERM STRATEGIES TO MITIGATE DROUGHT

42. Long-range f orecast : It is in purview of IMD and accurate oceanographic pre-monsoon conditions.Besides , date of onset and withdrawal of monsoon, accurate forecast about amount and distribution of rainfall in ensuing kharif season would be of great value for planners as well as farmers to develop contingent plans, rather a all season weather coat, for drought.as well as floods . IRS P-4 satellite with Oceansat OCM, MSMR sensor may prove of great value in studying ocean situation. Great emphasis is to be laid in future on long-range forecasts to combat drought. These forecasts are given for the benefit of farmers for planning their agricultural operations and crop selection and for planners for advance planning in case of an anticipated flood or drought Source- CAZRI,2000. Strategy to combat drought and famine

43. ALTERNATE LAND USE SYSTEM Practicing alternate land use such as agro-forestry, agro-horticulture and silvi -pasture would provide long-term drought proofing in the Indian arid zone.

44. Crop improvement for drought tolerance or escape, seed priming, early sowing, soil conservation practices including tillage which conserve moisture, in-situ moisture conservation practices and water harvesting and use of antitranspirants and reflectants are some of the mitigation strategies Breeding for drought resistance crop varieties i.e development of transgenic plants for drought tolerance Adoption of long term strategies like integration of small reservoirs with major reservoirs, integrated basin planning, etc. L ong range rainfall forecast can prove as a warning tool for drought mitigation Conclusion