Experience of using Adept + Mind and other fertilizers for potatoes on sod-podzolic sandy loam soils of the Polesia of Ukraine
Potato is a crop that is highly responsive to the application of organic and mineral fertilizers, which significantly increases the yield when they are applied. The main organic fertilizer for potatoes is manure and mineral fertilizers, which significantly increases the yield of tubers on light soils and somewhat less on heavier, cohesive soils.
However, the output of manure cannot fully satisfy the growing needs of agriculture. In this regard, humic fertilizers, the reserves of which in Ukraine are huge, are of great importance.
Research methodology
In order to study the effect of humic fertilizers on potato yield in sod-podzolic sandy loam soils, field experiments were conducted in 2019–2020 in the Zhytomyr region. The sod-podzolic soils on which the experiments were conducted are characterized by the following agrochemical indicators: pH (salt) 4.9–5.9, hydrolytic acidity 1.5–2.3 mg-eq, humus content 0.8–1.3%, easily mobile phosphoric acid 2.25–4.5 mg per 100 g of soil, gross nitrogen reserve 0.06%, easily mobile nitrogen 50–70 mg per kg of soil. The average annual precipitation (according to long-term data) is 573 mm.
The experiments were conducted in the Korosten district of the Zhytomyr region in the fields of economic crop rotation. The predecessor of potatoes was winter rye (after lupine fallow for grain). Fall plowing was carried out in September to the depth of the arable horizon (18–22 cm). In 2020, two options (No. 6 and No. 7) with the introduction of Adept + Mind (3 times) were additionally included in the experimental design.
One of the experimental raw material variants was taken from the Korostovsky peat mining district. Peat-manure compost was prepared 5 months before application to the soil by mixing peat with manure in equal weight shares (1:1) and placing it in a pile for ripening.
Yield results
| No. | Experimental variant | 2019 | Crop increase, 2019 | 2020 | Crop increase, 2020 |
|---|---|---|---|---|---|
| 1 | Control (without fertilizers) | 129.0 | --- | 151.4 | --- |
| 2 | Peat manure compost, 30 t/ha | 286.0 | 157.0 | 381.8 | 230.4 |
| 3 | Adept 2l/ha (3 times) | 321.2 | 192.2 | 361.6 | 210.2 |
| 4 | Mineral fertilizers, equivalent to 5 tons of leonardite | 380.6 | 251.6 | 316.4 | 165 |
| 5 | Adept (2l/ha) + Mind(2l/ha) (3 times) | --- | --- | 413.6 | 262.2 |
| 6 | Leonardite in nests, 2.5 t/ha | 322.4 | 193.4 | 328,0 | 176.6 |
| 7 | Leonardite in nests, 1 t/ha | --- | --- | 325.4 | 174 |
As can be seen from Table 1, humic fertilizers had a positive effect on potato yield. The application of Adept 2 l/ha (3 times) of humic fertilizers provided an increase in tuber yield (on average over two years) higher than from 30 t/ha of peat-manure compost. The yield increase from Adept was almost the same in the dry 2019 and favorable 2020, while from 30 t/ha of peat-manure compost in the dry 2019 it was almost three times lower than in 2020. This is explained by the fact that the powerfully developed tops at the beginning of the growing season in the variant with peat-manure compost in the dry 2019 began to experience a lack of moisture, wither and dry out earlier. This also indicates a positive effect of Adept on the drought resistance of plants.
Dynamics of yield growth
| No. | Experimental variant | Tubers, c/ha | Tops, c/ha | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 18.07 | 28.07 | 7.08 | 17.08 | 27.08 | Cleaning | 18.07 | 28.07 | 7.08 | 17.08 | 27.08 | Cleaning | ||
| 1 | Control (without fertilizers) | 25.0 | 51.8 | 78.6 | 108.5 | 136.1 | 151.4 | 47.2 | 70.7 | 94.2 | 90.8 | 66.7 | 22.2 |
| 2 | Peat manure compost, 30 t/ha | 46.6 | 113.8 | 181 | 249 | 344.4 | 381.8 | 138.8 | 199.4 | 260 | 243.2 | 222 | 94.4 |
| 3 | Adept 2l/ha (3 times) | 102.8 | 157 | 211.4 | 267 | 294.4 | 361.6 | 177.8 | 180.6 | 183.4 | 165.6 | 144.4 | 44.4 |
| 4 | Mineral fertilizers, equivalent to 5 tons of leonardite | 107.8 | 152.2 | 196.6 | 261.6 | 290.8 | 316.4 | 181.4 | 183.4 | 187.8 | 190 | 188.8 | 33.4 |
| 5 | Adept (2l/ha) + Mind(2l/ha) (3 times) | 161.2 | 225.8 | 290.4 | 355 | 385.6 | 413.6 | 247 | 300 | 273.4 | 237.8 | 233.4 | 55.6 |
| 6 | Leonardite in nests, 2.5 t/ha | 123.8 | 198.2 | 272.4 | 290.2 | 312.4 | 328 | 166.6 | 187.8 | 209.2 | 167.8 | 116.6 | 33.6 |
| 7 | Leonardite in nests, 1 t/ha | 105.6 | 171.2 | 237 | 294.4 | 312 | 325.4 | 122.2 | 146.2 | 170.2 | 152.8 | 127.8 | 38.8 |
The table shows that the most intensive growth of tubers and tops was observed in the variant with Adept (2 l/ha) + Mind (2 l/ha) (3 times). The growth of tops and tubers in the variant with 30 t/ha of peat-manure compost lagged behind the variant with Adept (2 l/ha) + Mind (2 l/ha) (3 times). At the same time, the dying off of tops in the variant with Adept (2 l/ha) + Mind (2 l/ha) (3 times) began earlier than in the variant with peat-manure compost. Thus, Adept and Mind not only increase the potato yield, but also stimulate its growth and development. High doses of organic fertilizers (for example, 30 t/ha of peat-manure compost) slow down the development of potatoes. At the time of harvesting, the largest amount of tops remained in the variant with 30 t/ha of peat-manure compost, while in the other variants the tops were almost completely dry.
Conclusions
- Adept and Mind, used for potatoes on sod-podzolic sandy loam soils of Polesie, are highly effective.
- Adept (2 l/ha) + Mind (2 l/ha) (3 times) provide a yield increase comparable to 30 t/ha of peat-manure compost.
- The effect of humic fertilizers was more pronounced in the dry year.
- The greatest increase in yield per unit of fertilizer was achieved with local application of leonardite into nests at a dose of 1 t/ha.
- Humic fertilizers stimulate the growth and development of potatoes, accelerating the increase in yield.
- An equivalent set of mineral fertilizers turned out to be less effective than humic fertilizers.