Do You Know Humic Acid Derivatives Are?
from CALIFORNIA FARMER

Agriculturists have long recognized the value of "humus" in their fertilizer programs. This has been demonstrated by the purchase annually of thousands of tons of manure. Growers also have recognized the possible harmful effects from overuses of phosphorus and potassium, which cannot be leached out, and an increase in salinity, according to University of California, Riverside, research scientists.

One of the important benefits realized from using manure is that manures are parent material for the synthesis of humic acid derivatives (HAD). Humic acid derivatives are mixtures of humic acid, ulmic acid, and fulvic acid, and are products or organic matter transformations by the soil microorganisms.

There are several ways to build up humic acid derivatives in soil - the application of manures, the growing of a soil-building crop such as a grass sod in rotation, the growing to maturity of green manure crops, or by applying concentrated Humic Acid material in the fertilizer mix.

Some organic deposits found in various parts of the world contain various percentages of humic, fulvic, and ulmic acids.

Humic acid derivatives have several known benefits to agriculture. University of California research scientists, scientists from other U.S. universities and European scientists have agreed on these benefits from the soil humus formation:

1.Improves soil physical properties.

2.Holds exchangeable plant nutrients.

3.Improves moisture conditions.

4.Affects the release of plant nutrients through slow decomposition by organisms, especially nitrogen release.

5.Improves trace element nutrition through chelation.

6.Has a growth promoting effect.

7.Has a high base exchange capacity - an important basis for soil fertility concepts.

When soils are intensively cultivated, the supplies of nitrogen, phosphorus and potassium will be depleted, and the concentration of Humic Acid will also decrease. This process is hastened by intensive cultivation characteristic of modern American agriculture.

Recently in California field tests, tomato yields were increased by 22 percent on cannery varieties and by 8 percent on green tomatoes harvested for the fresh market. This feat was accomplished by adding Humic Acid in addition to inorganic nitrogen, phosphorus and/or potash in the fertilizer program.

In greenhouse pot experiments at the University of California, Riverside, Dr. J.P. Martin, of the Department of Soils and Plant Nutrition, has found the Humic Acid in addition to inorganic fertilizer has improved growth of first crop (one year) citrus seedlings by about 20 to 25 percent, and a second cropping, in the same soil, by I00 percent or more. It was also noted in these tests that the plants with the Humic Acid maintained a darker green color longer. These experiments are still in progress.

More recently, however, University of California greenhouse and field experiments were initiated to study the effect of the material on the conversion, retention and release of nitrogen. James C. Bishop, associate specialists, Department of Vegetable Crops, UC Davis, stationed at the USDA Cotton Research Station at Shatter, said, "Recent observations in the field and in the greenhouse have indicated that Humic Acid has some effect upon the rate of change of nitrogen applied as urea, to the ammoniacal form and to the nitrate form. This is of particular interest at the present time when several "controlled availability fertilizers" are being provided by the fertilizer "industry." These experiments will be completed soon. It is also suspected that the growing plant can profitably use more nitrogen when that nitrogen is associated with Humic Acid.

Although more research is planned for the future, many farmers are now accepting Humic Acid as an integral part of their fertilizer program. The USDA and 21 universities have worked with or are still conducting experiments with Humic Acids.

Some of this research has shown that fruits and vegetables from plants grown with Humic Acid added to the regular fertilizer program had a longer shelf life, as compared to produce grown without the material. Evidence also shows an increased sugar content in strawberries and Thompson Seedless grapes for raisins.

Growers, during this decade, and surely in decades to follow, must consider all known avenues for more effective and efficient crop production. In the future, commercial Humic Acid materials will become more important in fertilizer programs that are designed to feed the rapidly expanding population.