13 March 2013 Blog
Becky Emerson Carlberg
The time is now to get that garden plot ready for action. If you have recently visited your local box store, you will find all types, sizes and compound formulations for amending your lawn, garden, tree and turf soils. Handy chemical mixtures packaged in ready-to-use containers. Do you know the origin of the factories that produce those man-made supplements? Munitions plants and newly created factories and power plants during WWII produced small arms ammo, explosives, detonators and artillery shells. After the war, many of these places were converted into fertilizer factories that chemically synthesized inorganic compounds. The basis for the very fertilizers you buy and distribute over garden soils. As an aside, artificial fertilizers now prop up nearly half the world’s population. Hmmm.
Why not use organic fertilizers? The report of the garden soil sample submitted to the Cooperative Extension Service in OKC by one family came back indicating some amendments were necessary for supporting a healthy garden. The nitrogen was very low, the phosphorus was double the ideal, and potassium was medium low. Why the emphasis on nitrogen, phosphorus and potassium? Of the 17 essential plant nutrients, these three are the most important macronutrients (calcium, sulphur and magnesium are secondary).
Nitrogen: Found in all proteins, a deficiency will cause slow and stunted growth with leaves showing more yellow (chlorosis) and less vibrant green. Nitrogen is required in the cell for making chlorophyll, the chemical that traps the sunlight in photosynthesis. It is a mobile element, so the older leaves will yellow first as what nitrogen is available heads down to the youngest lot. Excess nitrogen stimulates the plant to produce too much foliage, the leaves may look burned and the roots become stunted.
Phosphorus: This element is necessary for taking the energy from the sun and transforming it into the chemical driving energy of ATP in photosynthesis. In essence, it is needed for the growth of the plant and roots, flower and seed production. If too much phosphorus is present, the opposite of the chlorosis of nitrogen will happen. Leaves become TOO green! Too little and leaves die. As with nitrogen, phosphorus is mobile and effects are seen in the oldest leaves.
Potassium: Just like we humans need potassium in fluid regulation, plants need potassium to open and close their little stomata, the tiny holes that dot the plant surfaces. Stomata are lined by cells that look like lips, and these lips regulate water loss from the leaves. Very helpful in drought times. It too is very mobile and soluble, thus leaches out. Plant immunity is compromised and the leaves look wilty and sad.
Fertilizers are rated as 0-0-0 ratios, or N-P-K ratios. The first 0 = Nitrogen, the second = Phosphorus and the third = Potassium (the K is the chemical sign for potassium). It is all a balancing game, and soil tests give the deficiencies, normalities or excesses in N-P-Ks.
Information can be found on-line for organic sources of fertilizers. I took the liberty to look up a few:
Dairy manure. 9-4-10 ratio depending on amount of urine with the manure. Best if aged.
Chicken manure. 7-6-3 ratio. Fresh manure is high in nitrogen and can range up to 26-17-11. It too needs some aging. The best is to find scratched up, broken down and richly manured straw. Gardens love this.
Alfalfa meal. 3-2-1 ratio. Comes from fermented alfalfa plants and is considered a good soil amendment. Recommended for compost piles as it generates heat by incorporating microbial activity. I will say here that alfalfa pellets brewed with a few other organic things plus water can become very explosive if in a capped container. Full of life!
Chilean nitrate. 16-0-0 ratio. This is a weird one. One on-line source reported it is dried bird guano found in the desert? Desert? Wait. Yes, the Atacama Desert is a site, but this compound is found in Caliche mines or surface deposits of sodium nitrate that is combined with calcium carbonate (hard pan). Very soluble but watch for possible leaching problems if used.
Fireplace ashes. Can range to over 6% available potassium. They have a high alkaline pH and salt level. Very soluble. Be very careful when amending with ashes and avoid acid-loving plants.
Pro-Gro-5-3-4. Consider this an all-purpose fertilizer, but with only 3-5% nitrogen. It is composed of such things as dried whey, cocoa meal, compost, peanut meal, natural nitrate of soda, fish and animal tankage (what is tankage?), phosphate rocks, etc., ground shells, kelp meal, and potash. Good enough to eat.
Cottonseed meal. 6-2-1 ratio. Slow release and a good dependable fertilizer.
Legumes have nitrogen fixing bacteria. When in the presence of phosphorus, the fixation is enhanced. There are living plants that can be used as “green manures” versus brown dead, decomposing manures.
Cover crop. Plant in fall. Till under in spring. Reduces erosion and builds up soil.
Catch crop. Fast growing spring crop. Red clover (easy to establish) and buckwheat. Let grow, then till under. Adds nutrients such as nitrogen.
Smother crop. Weed control. These plants grow between the rows during the growing season.
Rainfall. Ha. Ha. Ha. But, if we are so blessed with good rains, remember that rainfall adds 10 pounds of nitrogen per acre in one year. Even if we get 50% average rainfall, our soils still might receive 5 pounds of N/acre/this year!
So, go organic this spring. Keep track of your soil amendments and watch how well your plants grow. Next year you may vary your approach, totally change it or stay with the plan. Good luck.