Potential of Conservation Agriculture in the Sloping Lands of Tanay, Rizal, Philippines

Last May 4, 2007, I was invited by Dr. Edna Samar of the Bureau of Soils and Water management Tanay Hilly land Station to talk about Conservation Agriculture (CA). In attendance are the hilly land farmers from Tanay and personnel from the local government Unit (LGU) of Tanay, Rizal. From my initial discussion with Dr. Samar, I learned that this will be the first time that Tanay farmers will be hearing something about CA, so I prepared an overview on CA. I intentionally avoided touching CA practices currently being used by the different countries. I focused on the three basic principles of CA as provided by the Food Agricultural Organization (FAO). The following is my presentation on this training-seminar.

I started with the key global issues Filipino people are facing. Demand for food is increasing, the land available is shrinking, but most of all, most of the productivity techno-how are already being utilized—improved varieties, fertilizer, and water. We expect that in the very near future, competition for water resources (surface and groundwater) will be more severe, Fossil fuels will be more costly and greenhouse gas emissions such as carbon dioxide, methane, and nitrous oxide will increase.

Farming faces a double challenge: increase production to meet food security needs as population growth continue to increase and preserve natural resources simultaneously by minimizing negative environmental effects and provide income to employ in agricultural production. There are means available such as the use of conventional or traditional tillage.

There are various reasons why farmers use tillage. To manage crop residues, prepare seedbed, loosen the soil for good aeration and enhanced decomposition and release of available nutrients from soil organic matter. Control of soil borne diseases and pests, and provide compaction relief (temporary) and for aesthetic.

But is tillage really necessary? If we look around, we can see something that will begin us to doubt the necessity of tillage. In fact, nature shows that plant growth is possible without any soil tillage (as in forest, grassland and shrub land). There is scientific evidence that water infiltration is highest on undisturbed soils under permanent soil cover (as in the wood land). Experiments have shown that soil tillage causes physical degradation of soil structure (destruction of soil aggregate leading to compaction and less water infiltration).

If tillage is not necessary, why did people till at all? There are quite a number of reasons why farmers till the land: to place the seeds into the soil and control weeds on a larger scale; tillage produced warming and aeration of the soil; caused mineralization and release of nutrients from soil organic matter. These are valid reasons, however, if we look at tillage detrimental effects on the environment and farmers such as the money it costs (fuel, repair, and cost of the operator, if animals are used, the costs of feeding and caring for the animals); global warming due to greenhouse gas emissions from the burning of the diesel fuel; decline in the amount of soil organic matter; disruption of the pores left by roots and microbial activity; breakdown of soil aggregates ( clogging of soil pores, reduced infiltration of water, runoff, soil erosion, soil crusts and forms a barrier to plant emergence). Tillage promotes water and wind erosion and even soil compaction; reduced capacity of the soil to regulate water and nutrient supplies to plants. Promote the loss of valuable plant nutrients and reduced biodiversity. There are many reasons that will lead us to believe that tillage is not necessary.

If tillage is not necessary, there must be an alternative to use to address the very reason why farmers till the soil. One possible solution is conservation agriculture (CA). According to FAO the aims of Conservation CA are: To conserve, improve and make more efficient use of natural resources through integrated management of available soil, water and biological resources combined with external inputs; preserve and improve the soil and the life associated with it; and minimize the negative effects of intensive farming.

From the definition provided by FAO, CA has three basic principles. 1. Maintaining a permanent or semi-permanent organic soil cover. This is done by growing crop or a dead mulch to protect the soil physically from sun, rain and wind and to feed soil biota 2. Reduce or eliminate of soil tillage. This can be accomplished by adopting the zero or minimum tillage and direct seeding. The soil micro-organisms and soil fauna take over the tillage function and soil nutrient balancing 3. Through varied crop rotation. Through proper crop rotation, we can avoid diseases and pest problems; and livestock production can be integrated and make use of the recyclable nutrients.

Conservation Agriculture has several benefits. CA reduces production cost by reducing the tillage work, particularly the costs of fuel, less application of herbicides. Planting can be accomplished in one pass of the seed drill. CA ha positive effects on the environment because the practice favors the capture of carbon in the soil due to the increase of organic material in its content and less use of diesel fuel and thus lower carbon dioxide emissions. CA boosts yields and incomes. Yields increased by an average of 79 per cent and harvests of crops such as maize, potatoes and beans doubled. CA has less reliance on costly pesticides (less damage to the environment) and demands less water. Yields are higher with no-till because of timelier planting and better stands.

CA improves soil quality. This can be observed in the improvement of the physical and chemical properties of the soil, enhancement in the stability of the surface soil aggregates, and increased activity of the worm population. The mulch helps promote more stable soil aggregates as a result of increased microbial activity and better protection of the soil surface. There is more biotic diversity in the soil as a result of the mulch and less disturbance. Surface mulch moderates soil temperatures and moisture, which is more favorable for microbial activity. In addition, gradual decomposition of surface residues improves soil organic matter status, biological activity and diversity. In addition, CA improves fertilizer efficiency

CA can be applied in all farm types and in all farming environments. Apart from the benefits mentioned above, CA holds tremendous potential for all sizes of farms and agro-ecological systems. The degree of success on individual farms depends on the individual situation of each farmer, including specific environmental and economic conditions.

For more info: Call: Dr. Gavino Isagani P. Urriza At: (02) 923-04-59 Or email us a gurriza258@yahoo.com or visit us at: conservationist.wordpress.com