Backgrounder
Many farmers grow healthier crops by using fertilizers. Fertilizers feed plants with nutrients to make them stronger. Usually fertilizers are mixed in with the soil and enter the plant through the roots.
But there is another type of fertilizer called “foliar” fertilizer which is applied to the leaves of the plants instead of to the roots. Foliar fertilizer enters the plant through small holes in the leaves called stomata. These holes open and close and are so small you cannot see them. Plants breathe through these holes. They also use the holes to take in nutrients from the air. Generally the stomata are open during the night and morning, but closed at mid-day to keep moisture in.
You can use foliar fertilizer to give your crop some extra nutrients from time to time to help them grow faster and stronger. And of course stronger plants can resist pests and diseases more easily. Foliar fertilizers usually contain nutrients that plants need such as iron, sulphur, nitrogen, and potassium. Giving the plants an extra dose of these nutrients will help them to grow stronger and healthier.
It is easy to make your own foliar fertilizer with the leaves of local plants.
In Guatemala, Pedro Rene Chalco Lopez in the Department of Sololá uses black nightshade (Solanum nigrum) to make foliar fertilizer.
Here is his recipe:
Chop up about 1/2 a kilogram of the black nightshade plant. Add four litres of water and boil the mixture for 15 minutes. Let the liquid cool. Filter out the liquid portion of the mixture. Add eight parts of water to this solution and put it in a sprayer. (Pedro puts two litres of this solution in a four gallon sprayer and then fills the sprayer with water.) Spray it on your plants. The best time to spray foliar fertilizer is late afternoon. Pedro recommends that you spray this fertilizer on the plants every five days from flowering until harvest. He uses it on soybeans, corn, and beans.
Remember to be careful when you use foliar fertilizers. They can burn the delicate leaves if they are too strong. For this reason foliar fertilizers are always diluted – they have just a little fertilizer and lots of water. After you’ve made a mixture add at least four parts of water to it. Experiment with different concentrations.
This is just one recipe that has been experimented with but there are many plants that could make good foliar fertilizers. You may have to experiment using different local plants before you find out which ones make the best fertilizers. Often leaves from leguminous plants are good to use. Prepare a solution and spray it on just a couple of rows of your crop. Mark the sprayed rows well so that later you can compare the sprayed and unsprayed crops and evaluate the effectiveness of the fertilizer.
Information sources
Pedro René Chalcu Lopez, Farmer, Barrio San Bartolomo, Sololá, Guatemala.
Fertilización organica (1992, 108 pages), published by ALTERTEC 3a Avenida 5-27, Zona 1, Guatemala City, Guatemala.