It's going to depend on the element of interest (e.g. N vs. Fe), and the plant involved (foliar fertilization may be less effective in crops with thick or waxy cuticles). Also, there's evidence that the addition of a chelate (e.g. EDTA) may help foliar fertilzation. Finally, there are practical considerations: foliar fertilization is often used in cases where there is a nutrient deficiency that needs to be corrected quickly but may not require a large dose of the element. Soil fertilization may be more effective for general nutrition.

Soil fertilization is more efficient and safer than foliar application because in just a little higher dose can severely hamper the plant growth.

The Soil fertilization and foliar fertilization depends upon the soil quality. The biological, physical and chemical properties of the soil are important to soil quality. Soil disruptions can cause reduced soil quality.

Following Number of methods are used for fertilization

1. Soil fertilization ,

2. Foliar fertilization ,

3. Trunk nutrition ,

4. Fertigation ,

5. Organic manuring ,

6. Integrated nutrient management

Above methods of fertilization have their own merits and demerits , depending upon the crop , soil conditions ,agro climate etc.

The efficacy of foliar sprays is largely dependent on following prime factors

1. Soil ,

2. Plant and Condition of the leaf surface

3. Environmental factors

4. The condition of the leaf surface, in particular the waxy cuticle

Soil fertilization is a technique of feeding plants by applying solid/liquid fertilizer directly to their roots Plants are able to absorb essential elements through their roots shells, bacteria. Soil fertilization is the traditional fertilization. Foliar feeding is a technique of feeding plants by applying liquid fertilizer directly to their leaves Plants are able to absorb essential elements through their leaves. Foliar fertilization does not substitute the traditional fertilization of grape production, but it does serve as a help to complete and guarantee the nutritional requirements of a cultivar which is often difficult to supply only through soil fertilization. In addition, this practice permits the application of relatively small amounts of the product in relation to the quantities which need to be supplied to the soil.The absorption takes place through their stomata and also through their epidermis. Transport is usually faster through the stomata, but total absorption may be as great through the epidermis. Plants are also able to absorb nutrients through their bark. Foliar fertilizers are completely soluble in water, and additionally the macro-and microelements in the form of chelate are very rapidly absorbed by plants. Foliar fertilization does not substitute the traditional fertilization of grape production, but it does serve as a help to complete and guarantee the nutritional requirements of a cultivar which is often difficult to supply only through soil fertilization. In addition, this practice permits the application of relatively small amounts of the product in relation to the quantities which need to be supplied to the soil.

Foliar feeding was earlier thought to damage tomatoes, but has become standard practice.

Both macro-and micronutrients can be delivered to plants by foliar fertilization. However, due to the fact that macroelements are absorbed by plants in much higher volumes they should be delivered to the plant with the soil fertilization.

many thanks to Salvatore S. Mangiafico, Bir Jahangir Shirazy, and Prem Baboo for their answers

Soil fertilization is the most efficient and most widely used for all types of fertilizers, while the use of foliar fertilization is mainly used for micro-elements first, as well as for use in cases of rapid treatment for the lack of some nutrients, as well as to avoid cases of fixing some elements in unavailable form on particles of some types of soils.

Remember that these two are importants, why ? let's to talk abou coffee or another , perennial crop, we need to put the fertilizer in the soil, but is very important to look if is necessary , increase nutrients in the leaf. Anyway is most better in soil, then in the leaf.

Thanks Ali and Gustavo Tonhão

Under such conditions, crop response to soil application of macronutrients can be very high but foliar feeding of micronutrients has been more effective and less costly than soil application

Soil fertilization d more effective. Plants are able take up the nutrients as they go into solution. However, like other contributors have mentioned, foliar is not as effective as soil fertilization. Foliar good for micro nutrients and not for thick cuticle

The soil fertilizer (soil fertility) is the capacity of soil to supply nutrients to the plants. The percentage contribution of nutrients from the soil is much higher than the nutrient supplied through foliar for obtaining crop yield. Though the application of nutrients through foliar have higher utilization efficiency, the foliar nutrients alone may not satisfy the complete nutrient requirement of any crop.

Dear: Dr. Majid

soil fertilizers is the main source for nutrients particularly the main elements, N, P, k and Ca

However, foliage fertilization used for micro elements to avoid fixing in soil like Fe in calcareous soil, and in case of nutrient deficiency.

Regards

Many thanks to all for your reply

To me, both are important. Soil fertilization usually supply all essential nutrients which are needed more for the survival of plant community and in cases of supply of micro-nutrients, foliar fertilization is preferably and may act promptly.

Excellent discussion, good information, following.

It depends on the biology of the plant too. For example, plants in the family: Orchidaceae and Bromeliaceae (e.g.: pine apple) will benefit more from foliar fertilization since their root system does not play a significant role in adsorbing nutrients.

just remeber the plant mouth is on the root system, always for all plants. As position.

The macro nutrients such as N P K are essential elements in soil fertility which are readily absorb in soil solution through the root systems which is more efficient due to large areas of soil explore by roots.whereas foliar fertilization is restricted to leaf surface areas which is smaller compare to soil areas. the foliar fertilization can easily be wash away by rain or evaporate by wind.

Many thanks Peter

We face many limitations for foliar feeding (humidity, temperature, wind, nozzle droplets size, pH of solution, leaf cuticle, leaf area,......) as it is not the suitable method for plant nutrition (Plant mouth is on the root system). On the other hand, some nutrients require a long time to be absorbed through the leaves. With the exception of nitrogen, other nutrients take several days to 50% of them be absorbed through the leaf feeding (Fe and Mo: 10-20 days, Zn, Mn, K: 1-4 days,...). Foliar feeding should be the complementary method for soil fertilization.

Soil is the media for plant growth...It is the natural three dimensional hub so as to sustain life of absolute producers of the food chain so called green chlorophylous plants..it is the house of beneficial microorganisms..Main process of nutrition in plants is mediated through the soil because of immense capacity of roots (especially root hairs) to absorb nutrients and water through many mechanisms..it is always said that "feed the soil rather than plants" is scientifically reliable statement in context of plant nutrition.. However, applied nutrients through said may undergo several losses, deficiency of which may reduce growth during the life cycle of a plant..to compensate these losses, application of nutrients over the shoot is done to supply nutrients through plant foliage, called as foliar application..Both soil application followed by foliar application is very good approach to supply nutrients in optimum amounts and in the right time so as to satisfy demand of crop with supply of nutrients..There are so many micronutrients which are applied through foliar drops to check deficiency without deteriorating production potential of a crop..So, main hypothesis behind nutrition of a crop is accompanied by the soil medium, but for getting advantages, both foliar application and soil application is required...

Hi

In my opinion, both of them (soil fertilization and foliar spraying) are necessary. Because there are advantages and disadvantages in both methods.

Foliar spraying: it is not possible to use of macronutrient in several time and higher concentration to provide plant requirement, and the cost of repeated spraying increases, and if the concentration of elements increases, we will face leaf scorch. Of course, it has advantages such as reducing the use of fertilizers and contamination of underground water, and less mobile elements such as iron and zinc are easily available.

soil fertilization: Although soil fertilization is basic, it has advantages and disadvantages. In soil fertilization, there is always a rich source of nutrients that cannot be absorbed easily, and the acidity of the soil must be adjusted in order to improve absorption. It is much more suitable for high-use elements. By using rotted animal manure, both the soil texture and the amount of elements can be improved.

but, some elements such as calcium, which are transferred to the upper part of the plant by mass flow, settling in the leaves and not reaching to the fruits specially under high transpiration condition, cause the formation of bitter pit and pitting of the fruit tissue, especially in apple fruit.

Therefore, it is necessary to use irrigated fertilizer to improve the absorption of macro elements and foliar spraying for micro elements applying and to use animal manure in the form of soil to improve performance.

best wishes