Conservation Agriculture and soil health examples from South Asia. Peter R. Hobbs

Transcription

1 Conservation Agriculture and soil health examples from South Asia Peter R. Hobbs

2 Future Agricultural Challenges To increase food production sustainably to meet food security and nutritionalneeds of a growing population now and in the future while at the same time minimizing the effectson the environmentand improving the livelihoodsof those involved in agriculture Estimates suggest 70% more food needed by Can only do that if: Improve the efficiency of natural resource use needed for agriculture through Sustainable Land management Reduce field and storage losses Transfer innovative management systems to farmers

3 Photo: John Morrison WHEN Demand for food increasing areas with food insecurity Harvested crop area per capita - shrinking Traditional sources of productivity growth are already Business being used? as usual will Competition and demands for blue water increasing Future oil price increases higher input and transport costs not get the job done. Impending climate change and more severe weatheras a result of GHG emissions Resource, environmental and land degradation already happening? Dietary changes towards more animal products Biofuel competing for agricultural land Less investment in research and human resource training

4 Sustainable Crop Production Intensification (FAO) Sustainable crop production intensification aims to maximize options for crop production intensification while minimizing the effect on biodiversity and ecosystem services.

5 Soil Health a Key Agronomic component but also moisture for plant growth An Unhealthy Soil A Healthy Soil

6 Degraded soil Healthy soil Low organic matter Poor physical properties Poor water infiltration Poor nutrient cycling Declining productivity More pathogens Nutrient deficiencies Low biological diversity Higher organic matter Improved physical properties Improved water infiltration Improved nutrient cycling Sustainable production Less pathogens Balanced fertility Good biological diversity Intensively mined agricultural soil No organic amendments Forest soil not disturbed Leaf mulch

7 Degraded soil Healthy soil No addition of organic matter Only use chemical fertilizer Excessive tillage Use of toxic pesticides Mining of soil nutrients by unbalanced fertilizer use Erosion wind or water Present farming practices?? Use of organic amendments Minimal soil disturbance Use of surface mulching Use IPM, IWM, IDM, ICM Rotations Nutrient balancing Sustainable Land Management like Conservation Agriculture or Resource Conserving Technologies

8 TILLAGE AGRICULTURE SOME CONSEQUENCES

9 Effects of Intensive Tillage Soil Organic Matter decline through mineralization and oxidation. Disrupts pores, root channels and fungal hyphae Raindrop impact break soil aggregates and help form surface crusts reduce infiltration and increases surface runoff. Leads to more wind and water erosion Soil Compaction Affect on the below ground biological system? Erosion soil loss

10 Wind Erosion Major problem of blowing dust in arid and semiarid regions especially where overgrazing, removal trees and shrubs and too much tillage. Dust storm in Afghanistan

11 Tillage Addiction: Downward Spiral in Soil Health Increased tillage Compaction Downward spiral of poor soil health Declining OM Poor drainage Reduced soil aggregation Unhealthy microbial communities

12 Is tillage necessary? CO 2 (Wayne Reeves, 1997)

13 Need to improve soil properties and soil biological diversity The importance of soil organic matter formation and the multitude of organism s involved fauna and flora Need for healthy roots and the synergistic associations with biological HOW organisms DOES eg. rhizobia, ONE mycorrhiza, IMPROVE anti-fungal agents etc. SOIL HEALTH? Soil microbes protect their own territory and through microbial competition maintain a balance that stabilizes the population Some microbes help roots to control disease anti-fungal agents A healthy soil has more microbes than an unhealthy soil Mulching helps promote more diversity of microbes

14 Life in Soil Highly complex and dynamic living system Sensitive to tillage, pesticides, and other toxins Increasing nutrient availability and plant productivity depends on regaining a healthy soil food web LIFE IN THE SOIL VIDEO

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16 Decades of success Legume/Rhizobium symbiosis

17 Extended hyphal network in Pine ectomycorrhiza Paul and Clark, 1994

18 Conservation agriculture? What is it? Minimal soil disturbance zero-tillage if possible just enough to get the seed in the ground Permanent soil cover residues of past crop or cover crop grown to provide cover. NO burning of residues Rotations mainly for residue pest, disease, weed control But still need to use integrated practices for weed, pest and disease control No burning of crop residues Needs flexibility in definition and adaptation to local conditions

19 Why Conservation Agriculture? To combat increasing land degradation (physical, biological and chemical) Sustainable intensification (more efficient use of resources) If properly managed, CA can reduce production costs CA is regarded as more water-, nutrient-, energy- and labor-use-efficient CA can reduce risk of crop failure CA can help mitigate and adapt production to climate variability. as a result of more efficient and productive use of water resources?

20 No-Tillage with Inverted-T in South Asia Based on inverted-t coulter from NZ Good where no loose residues including anchored straw Locally made and low cost Can adapt present farmer machinery Uses 15-25% less water Less weeds germinate Service providers means small farmers can use

21 No-Till Conventional

22 Phalaris population over time 2500 b 2000 Phalaris populat tion a 1 a a b b NT CT Tillage system

23 No-till rice-wheat In order to get the full benefit of no-till wheat, also need to no-till rice, BUT: Problems of weeds because difficult to pond water when no puddling Traditionally hand weeded Tedious and usually done by women One solution would be to introduce herbicide resistant rice varieties or find herbicides that work in no-till rice Use of cover crops

24 Other Future Issues Rice Better 0-till and DSR varieties Oryza sativa by O. glaberimma crosses Chromosome substitution lines Use of Genetic Engineering Roundup ready rice Blast resistant rice Drought tolerant rice C4 rice, Golden rice, N-fixing etc Improved equipment for seeding rice

25 Worldwide adoption of Conservation Agriculture Global CA Area in Million ha 155 million ha Year

26 Residue retention distinguishes Conservation Agriculture from conventional farming systems, which are characterized by leaving the soil bare and unprotected, exposed to climatic agents. The plant cover is not incorporated into the soil by tillage. Conservation agriculture is different from conservation tillage in that soil disturbance is less (FAO, 2002)

27 The importance of residue No-Till wheat with residue No-till wheat with residue removed Govaerts et al., 2005

28 Comparison of Rainfed Maize Production under the Common Farmer Practice versus Conservation Agriculture-based Crop Management in the Central Highlands of Mexico Zero Till; Residue Retention; Conventional Tillage; Residue Removal; Crop Rotation Mono-cropping of Maize

29 The importance of residue No-till maize with residue No-till maize without residue

30 Rainfall use efficiency.. No-till Conventional after 12 years of No-till 35% more infiltration Runoff Eastern Australia - Rainfed

31 The following crop in this trial site; Queensland Australia No till Conventional A maize/corn crop Zero-yield maize

32 CA is applicable to all farm sizes No-tillage on big farms with tractors

33 Small or big farms Tractor to manual or animal power Mono or mixed cropping Trees can be added Irrigated or rainfed Flat or raised bed planting Basins or mounds

34 An example of a way forward Zai systems: Hand-formed planting pits done in dry season Shaped to collect rainwater Filled with compost (farm yard manure) Crop hand sown directly into the compost and pit Conservation agriculture principles: Soil cover Direct sowing Permanent Basins? Source: ACT Photo: August Basson

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36 Another example of a way forward Ripping using animal power: Winter (off-season) plowing Direct sowing into lines opened with a ripper Occasional spot application of fertilizer Conservation agriculture principle: Reduced soil movement (during the crop season) Permanent soil cover in rest area to reduce erosion Photo: Richard Shetto

37 TIME REQUIRED TO OBTAIN FULL BENEFITS? 3-7 years? Possible transition period to get full benefits

38 Benefits from using conservation agriculture The following are typically (but not always) observed: Reduced erosion Increased water infiltration and soil moisture Reduced yield loss from drought Increased soil carbon Increased soil biological activity Improved soil fertility through microbial activity Reduced unit production costs Improved timeliness of operations Higher yields

39 CA performance with seasonal dry-spells, Monze, Zambia, 2009/ CA-Direct seeding, maize CA-Basin planting, maize Conventional ploughing, maize Rainfall in 2009/2010: 782mm Available soil moisture 0-60cm Available soil moisture (mm) Rainfall (mmm d -1 ) FC 50% avail. moisture PWP /11/09 23/11/09 07/12/09 21/12/09 04/01/10 18/01/10 01/02/10 15/02/10 01/03/10 15/03/10 29/03/ Date Thierfelder and Wall, 2010

40 Regional perspective Southern Africa, 80% positive maize yield responses to CA :2 line 1:1 line Conservation agriculture treatme ent yield (kg ha -1 ) Direct seeding Zimbabwe Ripline seeding, Zimbabwe Direct seeding, Zambia Ripline seeding, Zambia Manual direct seeding, Malawi Manual direct seeding, intercrop., Malawi Manual direct seeding, Mozambique Planting basins, Mozambique Thierfelder et al Conventional tillage yield (kg ha -1 )

41 Monze, Soil Carbon, 0-30cm, Total ca arbon (Mg ha -1 ) a a a b a ab b a a Year Conventional ploughing, maize (CPM) Direct seeding, maize (DSM) Direct seeding, cotton-maize (DSMC) Thierfelder et al. 2013

42 The use of CA principles in South Asia Use of crop residues (for feed and fuel) varies from East to West across the Indo- Gangetic Plains (IGP). Full CA is not widely practiced due to wide use of seasonal puddling, Zero Tillage (ZT) and its derivatives are increasingly practiced

43 CA in South Asia Happy seeder (4WT) BARI designed strip tillage seeder Happy seeder (2WT) Laser Land Levelling (before CA 2WT) The VMP

44 CA in South Asia 2 BFG PTOS (Permanent) beds Jab planter Dashmesh ZT Drill National 2WT drill

45 Resource Poor Farmers and CA? It is also possible for poor and resource poor farmers to benefit from CA, even those that don t have animal or tractor power. Do so by renting technology from service providers Can train and improve the performance of these entrepreneurs This is what has happened in South Asia

46 Conservation Agriculture Web site

47 Possible improvements in Jharkhand Soil health diagnosis and research on how to improve through management including vegetable growing soils Rain water harvesting to raise the aquifers and use extra water through irrigation in the dry season or to get seedlings ready for the start of the monsoon -earlier rice planting and harvest Research on plough pans and possible improvements in rooting and water availability after rice Direct or even zero-till rice using residue and rotations need for research on weed control and varieties Mechanization for no-till and DSR rice weeding, spraying, harvest, threshing and cleaning. Research on field and storage losses.

48 Thankyou