On fertilizing plants in the initial period of development with potassium humate, the Totem “Agro.Bio” preparation and organic substances

The works of scientists provide data on the significant effectiveness of the use of humic fertilizers for grain and vegetable crops, as well as for vineyards. We studied the effect of humic acid compounds, along with some other organic and mineral substances, on corn and other plants, using top dressing at the beginning of development by soaking seeds in solutions of these substances. We interpret this method as top dressing of plants in the very initial period of their development. We proceed from the premise that improving plant nutrition by using stimulants and nutrients in the initial period of development (seed germination, emergence of shoots), when young plants need an abundant supply of nutrients, should stimulate the processes of plant growth and development.

We conducted field and vegetation experiments.

1. Field experiments

The experiments were conducted over two years (2014–2015) according to the following scheme:

1. Control - sowing with ordinary dry seeds.
2. The seeds were soaked in water.
3. The seeds were soaked in a Totem Agro.Bio solution (concentration 0.0005%).
4. The seeds were soaked in a solution of potassium humate (concentration 0.002%).
5. The seeds were soaked in a solution of a mixture of salts containing NPK with a total concentration of 0.1 mol (the solution included KH₂PO₄ and NH₄NO₃ in equal proportions).

In 2015, the concentration of potassium humate used was 0.001%, and the NPK mixture was 0.075 mol. Corn seeds were soaked for four days at a temperature of 14–16°C. Before sowing, the seeds were air-dried. Sowing was carried out in warmed soil to a depth of 8 cm, with a distance between nests of 70 × 70 cm, two plants were left in a nest. The experiment was carried out on the experimental field of the micronutrient fertilizer manufacturer Agro.Bio in the Chernihiv region, on fallow land, after double spring cultivation according to predecessors: 2014 - alfalfa, 2015 - oats. The accounting area of ​​the plots was 47 m² in 2014, and 51 m² in 2015, with four repetitions.

Table 1. Effect of fertilizing in the initial period of development on the height and foliage of plants (2014)

Table 2. Effect of fertilizing in the initial period of development on the height and foliage of plants (2015)

In 2015, the experiment was conducted on unfertilized and fertilized backgrounds. Mineral fertilizers were added to the soil for cultivation at the rate of: 150 kg/ha of powdered superphosphate, 90 kg/ha of ammonium nitrate, and 60 kg/ha of potassium chloride.

Further care was the same in all experimental variants and consisted of double cultivation in two directions and double manual weeding in the nests; thinning was carried out simultaneously with the first weeding.

Phenological observation data show that in all experimental variants the emergence of seedlings accelerated in comparison with the control. In the variant with seed soaking with water the acceleration was one day, in the variant with Totem Agro.Bio the onset of emergence accelerated in 2014 by one day, in 2015 by two days, and the emergence of full seedlings by 2 and 3 days, respectively; in the variant with potassium humate the onset of emergence accelerated in 2014 by one day, in 2015 by two days; full seedlings by two and three days, respectively. In the variant with NPK fertilizing the onset of emergence accelerated in 2014 by 2 days, and in 2015 by 2 days; full seedlings by 2 and 3 days, respectively. In both years the emergence of panicles and the onset of cob formation in the experimental variants accelerated by 1–2 days in comparison with the control. On July 16, 2014, a census of the average number of ears formed in the plot was conducted, showing the following results: control - 18, water - 17, Totem Agro.Bio - 34, potassium humate - 34, NPK - 30.

Table 3. Effect of feeding in the initial period of development on the increase in dry mass gain (2014)

During the growing season, the height of the plants (tables 1 and 2) and the increase in dry mass (tables 3, 4) were determined several times. The data from these records show that the plants of the experimental variants grew and developed faster than the plants in the control, especially in the first half of the growing season; after the emergence of panicles and the formation of cobs, the differences persist, but become less significant.

Table 4. Effect of feeding in the initial period of development on the increase in dry mass gain (2015)

The cob harvest was harvested manually and recorded using the continuous counting method. Before harvesting, the density of the plants was recorded. The stalk mass harvest was harvested manually a little later and recorded in an air-dry state using the test plot method, their size was 11.8 m² in 2014, and 25.5 m² in 2015. The data on the cob, grain and stalk mass harvest are given in Tables 5 and 6.

Table 5. Effect of fertilizing in the initial period of development on the yield of cobs, grain and green mass (2014)

Note: m of experience - 4.1; P of experience - 4.5%.

The data of two-year experiments conducted in years with different weather conditions, in 2014, a dry year, and in 2015, a fairly wet year, convincingly show a significant effect on the growth, development and yield of corn by fertilizing in the initial period of development with a mixture of NPK salts, Totem Agro.Bio and potassium humate. From the data in Table 7, it is clear that the most significant increase in yield took place in the variant with NPK, the effect of Totem Agro.Bio and potassium humate was quite close. In the variant with soaking the seeds with water, a significantly smaller effect was obtained.

Table 6. Effect of fertilizing in the initial period of development on the yield of cobs, grain and stem mass (2015)

Note: m of the experiment (unfertilized background) — 2.45; P of the experiment — 2.7; m of the experiment (fertilized background) — 1.91; P of the experiment — 2.0.

Table 7. Effect of fertilizing in the initial period of development on the yield of cobs, grain and stalk mass of corn (average data for two years on an unfertilized background)

2. Laboratory experiments

For a more detailed study of the effect of potassium humate on plants, in particular to establish the optimal concentration of the solution when soaking seeds, a series of laboratory vegetation experiments were conducted with various crops: corn, buckwheat, sunflower, cucumbers.

Methodology of vegetation experiments: Plants were grown in glass vessels filled with 1.2 kg of calcined and washed quartz sand. Each vessel contained 25 corn seeds and 35 seeds of buckwheat, sunflower and cucumber. The experiments were repeated 3 times. The duration of the experiment was from 21 to 24 days. Buckwheat and sunflower seeds were soaked for 4 days, corn and cucumber seeds - 5 days at a temperature of 15-16 °C. The following amounts of solutions were taken: 45% for corn, 70% for buckwheat, 30% for sunflower, and 50% for cucumbers by weight of the seeds. Sowing was done to a depth of 1 cm. All variants of the experiment were watered evenly with distilled water.

Experimental scheme:

1. Control: soaking seeds in distilled water.
2. Control: soaking seeds in tap water.
3. Top dressing with salts containing NPK at a concentration of 0.075 mol.
4. Top dressing with a solution of potassium humate at a concentration of 0.004%.
5. Top dressing with a solution of potassium humate at a concentration of 0.002%.
6. Top dressing with a solution of potassium humate at a concentration of 0.001%.
7. Top dressing with salts containing NPK (0.075 mol) with the addition of potassium humate at a concentration of 0.001%.

Table 8. Effect of fertilizing in the initial period on growth, foliage and dry mass gain of corn

Corn reacted strongly to mineral salt fertilization (NPK), weaker effect of potassium humate in concentrations of 0.001 and 0.002%; the concentration of 0.004% already acts depressingly. Option 7 stands out in particular - the effect of potassium humate against the background of NPK, here the effect is higher than in the corresponding options separately.

The strong development of roots in young corn plants is noteworthy, exceeding the above-ground mass by dry weight from 121 to 199% in different variants. The root system especially increases in variants with humic acid, except for the concentration of 0.004% and in a mixture of potassium humate with NPK.

Table 9. Effect of fertilizing in the initial period of development on the growth, foliage and dry mass gain of buckwheat

Buckwheat reacts strongly to NPK fertilization and even more strongly to potassium humate fertilization at a concentration of 0.002%. A concentration of 0.004% has a depressing effect, 0.001% gives an incomplete effect. The combined use of NPK and potassium humate in this case does not have a special effect. The root system of buckwheat is much less developed than that of corn, accounting for 36.9 to 71.9% of the above-ground mass by dry weight. The root system especially increases under the action of potassium humate at a concentration of 0.002 and 0.001%.

Table 10. Effect of feeding in the initial period of development on the growth and dry mass gain of sunflower

The increase in the variant with NPK is low, the increase from the effect of potassium humate at a concentration of 0.002% is the highest; but also not very high. The combined effect of potassium humate and NPK gives a smaller effect than the effect of humate alone. Potassium humate at a concentration of 0.004% has a depressing effect. The roots of young sunflower plants are also less developed than those of corn. Their dry weight is from 28.1 to 69.2% of the weight of the above-ground mass. Unlike other plants, in the variant with NPK the roots are very well developed, making up 69.2% of the weight of the above-ground mass. In the variants with potassium humate, their development is approximately the same as in the control, only at a concentration of potassium humate of 0.004% they are much less developed.

Table 11. Effect of fertilizing in the initial period of development on growth, foliage and dry mass gain of cucumbers

Cucumbers respond well to NPK fertilizing and almost equally to potassium humate. The 0.004% concentration acts almost as well as the 0.002% concentration. The 0.001% concentration has a weaker effect. The combined effect of NPK and potassium humate exceeds, although not by much, the effect of individual components. The roots of young cucumber plants also develop more weakly than those of corn, making up 45 to 58% of the dry weight relative to the weight of the above-ground mass. The development of the root system increases in variants with potassium humate at a concentration of 0.002% and in a mixture of potassium humate + NPK.

Data from laboratory microvegetation experiments show that the optimal concentration of potassium humate for soaking seeds is 0.002%, a concentration of 0.004% in most cases has a depressing effect, and a concentration of 0.001% is not effective enough.

Buckwheat and corn react more strongly to potassium humate when applied to seeds, while sunflower and cucumbers react somewhat less strongly. The first two crops also react more strongly to NPK fertilizing.

An interesting point is the more effective combined effect of NPK and potassium humate, exceeding the effect of individual components. This phenomenon was especially strong on corn, weaker on cucumbers. On other crops, the combined effect of NPK and potassium humate is lower than that of one more effective component (sunflower, buckwheat).

Expanding research on the impact of humic and ascorbic acid compounds, as well as mineral salts containing NPK in the initial period of plant development - during swelling and germination of seeds - deserves serious attention and can serve as a basis for developing new methods for increasing the yield of agricultural crops.

Conclusions:

1. The optimal concentration of potassium humate when soaking seeds is 0.002%. A concentration of 0.004% in most cases has a depressing effect, and 0.001% is not effective enough.
2. Buckwheat and corn react more strongly to potassium humate than sunflower and cucumbers.
3. The combined effect of NPK and potassium humate often exceeds the effect of individual components, especially in corn and cucumbers.
4. The root system of plants develops more actively when using potassium humate in optimal concentrations.