Smart Farming Solutions

If you look at a bag of fertilizer, you will see labels with headings such as: 10-10-10; 16-8-8; 6-0-6. What this means is the percent concentration of nitrogen (N), phosphorous (P) and potassium (K) in that order. A bag of 10-10-10 has 10% nitrogen, 10% phosphorous and 10% potassium; the rest is filler such as lime rock, sand or sludge. Every nutrient adds to cost. For example a 50 lbs bag of 16-0-8 should cost less than a 16-8-8 because it does not have any phosphorous. To complicate matters, every manufacturer uses a slightly different composition from others and has a different coverage rate. Nitrogen is the most expensive component, so one way to compare apples with apples is to take similar compositions and compute the cost of nitrogen per pound. Example: You are looking at two 50 lbs bags of fertilizer. One is a 16-4-8 for $26.97 the other is a 20-5-11 for $29.99. In the first case multiply 0.16 (16%) nitrogen by 50 lbs = 8lbs of nitrogen. Divide $26.97 by 8 = $3.37 per pound of nitrogen. In the second case: $29.99/ (0.20x50) = $2.99 per pound of nitrogen. This means you are getting more bang for the buck with the second bag. Now divide your cost for nitrogen by the advertised coverage rate and you get your cost per square foot.
Liquid fertilizers are absorbed by the plants through leaves 10 times more efficiently than through roots. As a result, much less liquid fertilizer is needed to compensate for a deficiency. When comparing prices of fertilizers between liquid and dry, once again consider the coverage per pound of nitrogen, phosphate or potassium (based on which ever has the greatest concentration).
Slow release fertilizers are more desirable than dry or liquid fast release fertilizers. However, their costs are significantly higher. The choice depends on your time. Fast release fertilizers are most effective when applied in small quantities frequently.
Also consider the ingredients. For example, plants can absorb nitrogen in ammonium or nitrate form. However, the use of only one form can be detrimental to plant growth. So an ammonium nitrate combination is more desirable. Better yet, a calcium nitrate, potassium nitrate, ammonium phosphate and ammonium sulfate combination provide the essential macronutrients. Stay away from any muriate of potash, (potassium chloride), due to the potential salt damage from the chloride.
Finally, if buying dry fertilizers, strive for organic inert material. If you buy a 10-10-10, 70% of the bag is inert material such as sand, gypsum, lime rock or organic waste. Unless you are growing vegetables, which may come in contact with the soil, strive for organic inert fillers.
Remember that cheap fertilizers can cause more harm than good. In the end, you get what you pay for.

Plant growth can vary significantly depending the soil composition. This is perfectly illustrated with the basil plants in the picture. The two pots to the left have muck soil, rich in organic matter. The two pots to the right are filled with sand. The pots were seeded at the same time. As you can see, the growth rate difference is nothing short of remarkable.
Organic rich soils, those containing humus, are the best soils to grow most plants. They retain both moisture and nutrients. Humus particles are both positively and negatively charged. As a result, positively charged ions such as calcium, magnesium and potassium, as well as negatively charged nitrates and phosphates bind to their surface. Water is also held to the surface of the humus colloids. This physical property of humus prevents leaching of nutrients and retards water evaporation. Humus soils are also rich in microbial life, essential for the transport of nutrients to the root zone, and nitrogen fixation.
Sandy soils on the other hand have no physical means of retaining water, nutrients or bacteria. Nutrients are rapidly leached with rain; and the soil also rapidly looses moisture. Nevertheless, some plants (such as cucumbers and tomatoes) thrive in this environment as long as moisture and fertilizers are available.
I find that most potting soils on the market are too light of a mix to grow garden vegetable without constant watering. This can be remedied using Hydretain. Hydretain is a remarkable liquid humectant, which retains moisture at the root zone and limits moisture evaporation. Unlike polymer beads that must be incorporated in the soil at time of planting, it can be sprayed on the lawn or pot at any time. Hydretain is a huge hit with golf course superintendents because they can cut their water use by 50% to 70%, saving them tens of thousands of dollars in water cost every year.
Another solution is to make your own mix, specific to the plant you want to grow. For example, for tomatoes, I combine an equal mixture of potting soil, backyard sand and topsoil (muck). This gives me a good balance between drainage and nutrient retention. I also add Inoculaid at planting and every two weeks thereafter. Inoculaid is a newly available strain of beneficial bacteria, that create moisture in the soil and turns nitrogen in the atmosphere to ammonia that the plants uptake. As a result, I cut my fertilizer use in half. Another reason for using Inoculaid is that the beneficial bacteria attack harmful pathogens. I no longer use fungicides, even during our hot and wet summers.
So before buying any potting soil, first determine the plant’s needs in term of water and nutrients and also consider your climate. For example, if you live out west in a desert or semi desert conditions, a typical peat potting soil will fail to provide the necessary moisture. In such case, making your own mix may be more appropriate.