Rethinking Water Use in Agriculture

No one seems to be thinking about a rain dance yet, but our taps are about to run dry. They are rationing water in Metro Manila. Now who would have thought we would have a shortage of water? Fresh water always seemed like a waterfall- infinitely gushing out of rocks. It is July 2010 and our dams are dehydrated, experiencing a historical record low. In the meantime, there will be 12 million people in Metro Manila, drinking, bathing and washing from Angat Dam’s reservoir. They have tightened our taps to give us 30% less and the problem seems negligible. Don’t run the taps while I brush my teeth. No more soaks in the tub. Change showerheads. Schedule laundry. Reuse gray water. But the seemingly slight problem of having less water to bathe, drink and wash with, dwarfs the bigger problem of Climate Change and food security, which has a lot to do with water.

Agriculture accounts for drawing 70% of the world’s fresh waters. Fresh water irrigates our lands and provides food for the world’s exploding population. As our population grows, so will our food requirements, and so will our demand for water. And as more water is drawn than is given, we will have to do with less for growing our food. Our farm tries to be a conscientious consumer. We try to draw just enough water to quench the thirst of our greedy plants. With a few water conservation and harvesting methods that rely more on Green Water rather than Blue, we would like to think our water does not just go down the drain.

Good soils can capture, hold and store water better. The secret to needing less water is having rich living soil. This we do by having more organic matter in our soil.

TRICKLE IRRIGATION

Farms traditionally used elaborate irrigation systems, which were designed when water supply was plentiful. Trickle irrigation is an innovative and efficient method of irrigation. It is called “trickle” because water drips slowly directly to the roots of plants through pipes (with small holes.) You save water because water drips directly where it’s needed. There is no runoff or wasted water. You also reduce evaporation, soil erosion and deep drainage. This method helps us get rid of many foliar or root diseases that spread through the water. Trickle irrigation also uses a lower pressure than other methods of irrigation, thus reducing energy costs as well. Some people find the “trickle irrigation” installation costs expensive. However, the initial investment is easily paid off with savings in water, energy, and the priceless value of saving the environment too.

IRRIGATION SCHEDULING

We schedule our work in the farm so we take advantage of the natural cycles. Evaporation depends on the climate, temperature and humidity. As there is less evaporation at night, we irrigate our plants closer to the evening so we decrease the loss of water through evaporation. A full moon means there is an increase in the water element. We sow our seeds two days before a full moon to take advantage of the water. A new moon means more water in the soil. Two days before a new moon, we do our transplanting to take advantage of the soil’s increased water content.

MULCHING

Mulch on the beds

Our mulch consists of weeds, flower trimmings, legumes, rice hulls, and wild sunflowers. We apply the mulch to our flowerbeds in layers of 2-4 inches. Mulching saves our water by helping our soils retain much of the water they get. I have read that a layer of mulch can reduce water evaporation by as much as seventy (70%) percent! Not only that, mulching is also fertilizer, and thus improves our soil by helping break down nitrogen and releasing more nutrients.

RAIN HARVESTING, GROUNDWATER RECHARGING AND CANAL LININGS

Raised beds for less tilling; Contour farming and Canals

Rainwater falls from the rooftops of our greenhouses straight to micro basins or canals, which catch them. We also ensure that we line the canals with thick mulch (4 inches at least) to ensure less evaporation. Since our greenhouses are constructed on a slope, the rainwater gently seeps towards and is absorbed by our flowerbeds.

TERRACING, CONTOURING and MICRO BASINS

We take advantage of the natural sloping topography of our farm to direct precipitation run-off to our flowerbeds. To prevent soil run-off however, we have planted legumes to act as breaks.

NATURAL WINDBREAKS

We have planted legumes in between our greenhouses and at the boundary of our farm to act as windbreaks. The windbreaks again reduce evaporation.

CONSERVATION TILLAGE

We have raised beds our flower beds so our flowers get more aeration in its roots. By doing so, we do not need to till as often, and we protect our topsoil. A good topsoil won’t be washed out by rain.

WATER-FREE TOILETS

Why waste perfectly clean water and flush dirt down the drain? Our toilets are water free. Waste is caught by sawdust treated with beneficial microbes to hasten decomposition. And because the waste matter and sawdust has been treated with microbes, there is no smell. People use about 6 liters of water per flush. Since we opted to use a no-flush, water-free toilet, we save approximately more than 8,000 liters of water per year.

WATER AS NEEDED

I believe there is enough water for everyone. There should be. But just like money, just like oil, and just like any other precious resource, we do not know how to handle it, splurging and exploiting it to excess, while denying it’s wealth to the rest of the world. Our farm’s method hopes to improve on the way we use water, drawing only as much as we need, and putting the water we get to efficient and productive use. Take only what you need and pay it forward.