Ideal Organic fertilizer for vegetables and fine herbs

Ideal Organic fertilizer for vegetables, as fine herb and vegetable plants progress from vegetative growth to flowering and fruit production, fertility rates and ratios vary for each crop. Here’s what most greenhouse vegetable and herb gardeners consider when looking at their fertility programs.

Influence of the substrate

The substrate is an important parameter to consider in a fertility management program. Inert substrates, such as perlite and stone wool, have little or no cation exchange capacity (CEC). Therefore all provided nutrients are only found in the substrate solution. On the other hand, organic substrate components such as peat fiber have a CEC of 200 meg. / 100 g, which means that they will retain some cations (NH ₄, Ca, K, Mg, and Na) and will release them back into the substrate solution to maintain their equilibrium with anions. EC and pH are relatively easy to handle on inert substrates because there are some exchange and buffer capacities. Therefore those parameters can be changed quickly. In contrast, substrates with minimal or medium CEC will have the opposite effect.

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When bark or compost is used as a component in a growing medium, it must be fully composted, or it will continue to compost in the container, starving the crop of nitrogen and creating heat that can damage or kill the roots of the plant. Other problems using partially composted bark or compost can include the initial salt content (EC), the source, and its chemical characteristics, which can be problematic for plants.

Water quality

Before establishing a fertilization program, it is essential to know the content of the irrigation water’s beneficial and trace elements. Water can contain nutrients that plants need, such as Ca or Mg, but its alkalinity impacts the substrate’s pH. If reverse osmosis water is used, the fertilizers used are even more important, and it is recommended to use a neutral fertilizer to minimize pH fluctuation.

Seedling fertilization requirements

The seedlings do not need fertilizer when they are sown until the end of the first week after germination. The cotyledons (which are performed within the seed) have all the initial nutrition necessary to support the seedlings’ growth. One week after germination, the seedlings require a small number of nutrients, mainly N, P, and K (between a quarter and a half of the amount needed during the active phase of growth, flowering or fruiting). Remember, seedlings and plants will not grow faster or better when you apply a higher amount of fertilizer than recommended; in fact, the over-application of fertilizer can harm growth (more vegetative or deformed plants), a reduction in fruit production, more bug problems, and a build-up of fertilizer salts that can burn roots and kill seedlings.

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Young seedlings are susceptible to high levels of fertilizer or salts in the substrate, so the electrical conductivity (EC) must be below 1.5 dS / m (mmhos / cm), using method 2 :1. Seed germination substrates, such as PRO-MIX PGX and PRO-MIX FPX, contain a light starter fertilizer load to meet the initial nutrients needed from seedlings until the formation of the first set of true leaves.

Design of a fertility program

Large greenhouse gardeners prepare their own nutrient solutions from scratch. The nutrients are normally separated into three tanks of concentrated solution:

• Deposit A: calcium, nitrogen, and iron.
• Then Deposit B: potassium, phosphorus, sulfate, magnesium, and micronutrients.
• Deposit C: acid.
• Organic fertilizer for vegetables.

It is important not to mix calcium with phosphate or sulfate or iron with phosphate, as they can form precipitates. The components of the water-soluble fertilizer must be used as they are injected into the irrigation system. Fertilizer solubility is influenced by temperature (more solubility at higher water temperatures). The amount of fertilizer that can be dissolved per liter of water varies depending on the fertilizer source. Normally, the fertilizer elements are injected into the irrigation system in a ratio of 1: 100; This means that one liter of a concentrated solution will be mixed for every 100 liters of water.

Fertility program considerations

Fruit vegetable plants use 50% N for their leaves and the other 50% for their fruits. On the other hand, leafy vegetables and herbs use 100% N for their leaves. So they need almost the same amount of N, K, and Ca. The flavor of vegetables and herbs can be improved if these plants are stressed with excessive fertilizer applications. However, this stress reduces fruit weight and the size of leafy crops.

Calcium is an immobile element within the plant. This nutrient deficiency can be observed even if the correct amount of Ca is added to the concentrated nutrient solution. The absorption of calcium is highly dependent on the transpiration of the plant. When calcium absorption is low due to slow perspiration during cold and cloudy weather or when it is hot and dry, but the plant cannot obtain water, a calcium deficiency will be induced, which can cause blossom end rot in tomatoes, peppers, squash, etc.

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During winter Vegetables and fine herbs require less water than in summer due to the reduced amount of perspiration. However, nutrient application amounts are the same throughout the year, as a crop’s nutrient needs do not change much from summer to winter.

This is especially because a greenhouse helps the horticulturist to be less dependent on the outside environment (temperatures, light, day length, rainfall, etc.) and can provide an optimal growing environment throughout the year.

Because plants use less water in winter and nutritional needs do not change, they feed slightly higher than in summer to not run out of nutrients between water applications.

It is also recommended that the leachate have an EC that is one unit higher than the input EC of the nutrient solution. It is best to test the EC and pH of the inlet (at the time of irrigation) and leachate every day, and make adjustments as necessary.

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These tests can also check the proper operation of the injectors or the actual concentration of the nutrients.

Finally, it is recommendeTheseamples to also the laboratory every two weeks and, if necessary, make adjustments to the fertility program. Don’t change the nutrient content drastically! It is better to change it gradually. Ideally, plants will respond to these changes in about two weeks. Send more samples to the lab to see if corrections have been made or if additional adjustments are needed(Organic fertilizer for vegetables).