Understanding the land

September 25, 2003

By CHARLA BORCHERS LEON

Victoria County Master Gardener

Aside from an avid passion for flowers and foliage of color in my landscaped yard, I became a certified Master Gardener to learn more about grasses and foliage not only on ranch land, but also in my own yard and landscape setting. Soil and water issues, as well as fertilizing practices, have also had a role in that picture. The "love of the land" information contained in this article is natural to me; the more scientific material has been learned from various Master Gardener sources.

Fourth generation in a South Texas ranching family, I have a natural love for the land. I know its value to be far more than what it produces or even what it could bring if ever transferred to another owner. To me, it symbolizes a part of nature and the world in which we live; it provides for the basis of a way of life. Following from this statement, I am of the opinion that, as co-inhabitants of an earthly home shared with other living creatures, we have a critical responsibility to help conserve and preserve land and the natural habitats of the other living creatures that thrive on it. Mother Nature's maintenance of grasses, plants and foliage in a natural environment is prevalent in untouched, open pastures with natural ecosystems. It is in cultivated or improved lands, including landscapes, that soil, water supply and proper application of fertilizers are basic management tools for productive plant growth.

The importance of soil cannot be overemphasized when trying to maintain the land and healthy plants, whether it is at the ranch or in a landscape. As a physical anchor for plants, soil is the primary source of water and nutrients. A soil in good condition for plant growth contains approximately 50 percent solid material including minerals, organic matter and microorganisms, and 50 percent open or "pore" space for the coexistence of both air and water.

Soil structure, which defines how tightly or loosely the soil is held together, can dictate how well plants respond. Good soil structure allows favorable movement of air, water and plant roots while poor structure slows down such movement. Good soil structure is almost always promoted by working into the soil additional organic matter - something that can be done easily in landscapes.

"Cover" crops like ryegrass also can be planted in open garden areas to help reduce erosion and loss of topsoil. Mulching is a standard practice for vegetable gardens, flower and shrub beds, and around fruit and ornamental trees. Two to four inches of organic mulch added twice a year is recommended for most garden and landscape plants. The continuous and repeat addition of these practices can raise the soil nutrient level and enhance the physical structure to such a degree that the need for synthetic fertilizers is greatly reduced, or even eliminated.

Soil drainage and soil depths are other issues influencing plant productivity. The amount of moisture that drains into and off the soil as well as the depth of the topsoil and root penetration determine nutrient and water availability for plants in the soil.

Plants feed on 16 nutrients or elements for normal growth. Of these, nitrogen, phosphorus and potassium are considered major nutrients because plants require them in larger quantities for maximum growth. Calcium, magnesium and sulfur are the next level of nutrients needed by plants. Therefore, it is these that are to be observed more closely to maintain soil and plant health.

The soil pH level, or acidic and alkalinity level in the soil, also affects the quality of plant growth. Soils with a pH level of 7 are neutral, between the scale of extremely acid (0) and extremely alkaline (14). Soils with a pH of 6 to 7 are ideal for most plant growth, although some grow well slightly below 6 and some do well just above 7.

By learning the nutrient and pH levels in soil, fertilizers or other products that can correct deficiencies or abnormalities for increased plant productivity can be added. The type of fertilizer needed depends on nutrients needed, soil structure and chemistry and even the method of applying fertilizer, of which there are various kinds, applications, and timing periods for best results.

Why all of this textbook information on soil and its nutrients? It is just a "scoop" full of knowledge that can be obtained from a soil sample test that will supply you with enough information to make a wise choice with regard to applications of soil modifications and fertilizers. The results will recommend to you what kind of fertilizer, if any, to apply for healthy plants in your landscape or garden. A soil sample test performed every three to four years in your landscape provides a map of historical and future fertilizing practices and gives recommendations to correct problems.

Results of a recent, similar soil-testing campaign through Texas Cooperative Extension in the city of Dallas showed 75 percent of all samples to be high or very high in phosphorus, indicating these samples do not need any phosphorus, including organic matter, for at least several years. Of those testing high in phosphorus, 10 percent also tested high in nitrogen, suggesting that these soils have been excessively fertilized in the past and changes need to be made or production will continue to falter.

In addition to causing plant growth problems, high nitrogen and high phosphorous levels in the soil can also lead to groundwater contamination, which eventually affects streams, rivers, estuaries and bays. While essential nutrients for plant life, they are known pollutants when mismanaged and can cause an imbalance in ecosystems with plant and even animal death.

Let's see what soils in our part of Texas will indicate. Remember to get your soil sample bags and information sheets from area Extension Education offices and participating local nurseries and feed stores. The accuracy of the test is a reflection of your sample taken. Sample the soil from about 10 random areas in your landscape or garden up to a depth of 6 inches. Avoid areas used for special features of your garden like gravel pathways, near brush or compost piles or under eaves. Place the samples in a clean plastic bucket or similar container and thoroughly mix the soil. From that mixture, place about a pint of the mixed soil in the soil bag, fill out the necessary form and drop it off with $6.50 to one of the area locations where the bags are being distributed and collected. Your final deadline is Oct. 3. It will be well worth your "dig in the dirt."

With some 168 million acres of land in Texas, there obviously are many different kinds of soils in our vast state. Knowledge of soils is very helpful in making decisions about our own gardening and landscaping. For best results, every home and business owner should apply this knowledge to every landscape.

This knowledge also stems back from gardens and landscapes, suitable to the protection of natural habitats, to the ranch land that I, like others who are its stewards, hold so dear. I leave with you a quote from a member of my ranching family who says that all the deeds, leases and documents that we have on land really are not worth their paper: "We are only stewards of the land, put here on earth to return it, in time, in a better condition than the way we found it."