Introduction
Humic organic matter, including humic acid, plays an effective role in improving the physical and chemical properties of soil, by the interaction of these compounds with soil minerals and then improve the physical properties of the soil as well as the adsorption capacity of mineral elements, humic organic acids affect the improvement of plant growth and the availability of elements. Humic acid is a complementary source of polyphenols in the early stages of plant growth, acts as a chemical intermediate, leads to an increase in the vital activity of the plant, as the enzyme system becomes more effective, cell division increases, the root system develops, and dry matter production increases. Organic acids increase nutrient availability as well as act as a buffer against changes in soil reactivity, as well as preserving nutrients from loss to the bottom away from the roots, for its ability to hold ions on its surface, many researchers have reached, that the organic and biological fertilization led to an increase in the concentration of element availability in the soil when planting.
Maize (Zea mays L.) is one of the most important Cereal crops on the world for its numerous utilizations: in human or animal food as green fodder or silage. Yellow maize occupies the second place in the world in terms of cultivated area and the first in the world in terms of production The global area cultivated for yellow corn in (2016) of grain yield reached 7.296 tons ha-1, in some developed countries, such as the United States of America, global productivity may reach double, while the productivity rate in Iraq was 3.425 h-1, despite the great importance of this crop and the growing interest in its cultivation in Iraq, however, its production rate is still low per unit area for many reasons, including the lack of productivity of cultivated varieties and not adding the appropriate amount of fertilizers, especially chemical ones that contain elements (NPK), with the neglect of foliar feeding, which plays an important role in increasing the quantity of the crop and improving its qualityLikewise, not choosing the dates for adding fertilizer at the appropriate or critical stages of plant growth that greatly affect its productivity.
Corn flour was used in the production of bread after mixing it with wheat flour, corn starch is used in making pastries and various foods, the sugary juice is extracted from its stems and oil from the embryo of its seeds, in addition to using its stems and leaves in the manufacture of different types of paper.
Humic organic matter, including humic acid, plays an effective role in improving the physical and chemical properties of soil, by the interaction of these compounds with soil minerals and then improve the physical properties of the soil as well as the adsorption capacity of mineral elements, humic organic acids affect the improvement of plant growth and the availability of elements. Humic acid is a complementary source of polyphenols in the early stages of plant growth, acts as a chemical intermediate, leads to an increase in the vital activity of the plant, as the enzyme system becomes more effective, cell division increases, the root system develops, and dry matter production increases. Organic acids increase nutrient availability as well as act as a buffer against changes in soil reactivity, as well as preserving nutrients from loss to the bottom away from the roots, for its ability to hold ions on its surface, many researchers have reached, that the organic and biological fertilization led to an increase in the concentration of element availability in the soil when planting.
Materials and Methods
The Experience Factors
The First Factor
Four cultivars of maize (Zp, Maha, Kaws and Forat) and the following codes were given (V1, V2, V3, V4) respectively, and they were cultivars approved by the Ministry of Agriculture and their source is the Agricultural Research Department, Department of Yellow Maize.
The Second Factor: Levels of Fulvic Humic Acids
- Control Without adding (T1) comparison.
- 1 g L-1 (T2) of fulvic and humic acids.
- 2 g L-1 (T3) of fulvic and humic acids.
- 3 g L-1 (T4) of fulvic and humic acids.
Agricultural Operations
Cultivation took place in the middle of March, the spring season, and the experimental land was prepared in terms of plowing, smoothing, and leveling as needed, fertilized the field with compound fertilizer (NPK) and urea fertilizer 100 kg per dunum, in three batches, the first at planting, the second after a month of planting, and the third at the beginning of flowering, in the form of a row.
| Chemical properties | Physical properties | ||
| Available Nitrogen | 2.08 | Sand | 16.00 |
| Available Phosphorus | 0.33 | Silt | 39.70 |
| Available potasium | 1.13 | Clay | 44.30 |
| Organic matter | 12.80 | ||
| pH | 8.35 | Soil texture | Silty clay |
| EC | 3.47 |
The Traits Studied are Traits of Growth
- Length of ear
- 1000 grains weight
- The biological yield
- The grain yield
- Nitrogen %
- Protein %
- Oil %
Results and Discussion
Length of Ear
Table 2. showed that there were significant differences between cultivars, and also the interaction between them in the length ear flowering. Table 2. showed a significant superiority among the cultivars in the length ear, where the Maha and Kaws cultivar was superior, as it gave 20.48 and 20.98cm, while the cultivar Forat gave the length of ear 18.77cm. The results showed that there was a significant interaction between the levels of humic and fulvic acid and the cultivars, the combination (T4 × Kaws cultivar) gave the length ear 21.67cm.
| V | T1 | T2 | T3 | T4 | Average |
| V1 | 20.47 | 20.73 | 17.73 | 18.80 | 19.43 |
| V2 | 20.67 | 21.13 | 19.40 | 20.73 | 20.48 |
| V3 | 20.60 | 19.97 | 21.67 | 21.67 | 20.98 |
| V4 | 17.00 | 19.40 | 18.81 | 19.87 | 18.77 |
| Average | 19.68 | 20.31 | 19.40 | 20.27 |
1000 Grains Weight
Table 3. showed significant differences between the levels of humic and fulvic acid, and the cultivars and the interaction between them did not show significant differences in 1000 grains weight.
Table 3. showed a significant superiority of the levels of humic and fulvic acid in 1000 grains weight, where the 3 g treatment excelled and gave a 1000 grains weight of 449.9 g, while the control treatment gave the lowest 1000 grains weight of 341.7g , perhaps the reason is due to the effect of humic acid in increasing the vital activities of the plant and raising the rate of absorption of nutrients, which leads to an increase in 1000 grains weight as this result agreed with what was reached by.
Table 3. showed a significant superiority among the cultivars in the 1000 grains weight, wherethe Forat cultivar was superior, as it gave 444.7 g, while the cultivar ZP gave the 1000 grains weight 352.5 g.
| V | T1 | T2 | T3 | T4 | Average |
| V1 | 300.4 | 337.2 | 373.0 | 399.2 | 352.5 |
| V2 | 340.9 | 383.9 | 440.8 | 481.1 | 411.7 |
| V3 | 356.7 | 429.5 | 441.7 | 441.5 | 417.3 |
| V4 | 368.9 | 468.3 | 463.8 | 477.8 | 444.7 |
| Average | 341.7 | 404.7 | 429.8 | 449.9 |
The Biological Yield (kg.h-1)
Table 4. showed that there were no significant differences between the levels of humic and fulvic acid and between cultivars, and the interaction between them in the biological yield.
| V | T1 | T2 | T3 | T4 | Average |
| V1 | 16133 | 16067 | 20378 | 22924 | 18875 |
| V2 | 17026 | 19555 | 21000 | 20289 | 19468 |
| V3 | 14689 | 21511 | 19089 | 19111 | 18600 |
| V4 | 14378 | 16222 | 15911 | 15582 | 15523 |
| Average | 15557 | 18339 | 19094 | 19476 | |
The Grain Yield (kg.h-1)
Table 5. showed that there were significant differences between the levels of humic and fulvic acid, between the cultivars and no significant differences of interaction between them in the grain yield (kg.h-1). Table 3. showed a significant superiority of the levels of humic and fulvic acid in the grain yield(kg.h-1), where the 3 g treatment excelled and gave 7239.75kg.h-1 , while the control treatment gave the lowest 5994.44 kg.h-1, Increase the rate of carbonation and this increases the yield of the plant.
Table 5. showed a significant superiority among the cultivars on the grain yield(kg.h-1) ,where the Forat cultivar excelled as it gave 9089 kg.h– 1 ,while the Kasws variety gave the least in the grain yield 5311 kg.h-1
| V | T1 | T2 | T3 | T4 | Average |
| V1 | 4244.44 | 4755.56 | 5400.00 | 6844.44 | 5311.00 |
| V2 | 5133.33 | 5368.89 | 6444.44 | 6311.11 | 5814.25 |
| V3 | 6244.44 | 8755.55 | 6248.89 | 6933.33 | 7045.50 |
| V4 | 8355.55 | 9422.22 | 9711.11 | 8866.67 | 9089.00 |
| Average | 5994.44 | 7076.75 | 6951.00 | 7239.75 |
Nitrogen %
Table 6 showed that there were significant differences between the levels of humic and fulvic acid, and between cultivars, and the interaction between them in nitrogen percentage.
Table 6 showed a significant superiority of humic and fulvic acid levels in nitrogen percentage. Where the treatment of the third level excelled 3 g gave the highest percentage of nitrogen 1.4592%, while the comparison treatment and the control gave the lowest percentage of nitrogen 1.0700%, and this is consistent that adding humic acid to the soil or spraying on the leaves led to the accumulation of nitrogen in the leaves of yellow corn.
Table 6 showed a significant superiority among the cultivars in the percentage of nitrogen %. Whereas, the Kaws variety was superior, as it gave 1.3142% nitrogen. While the zp cultivar and the Maha cultivar gave the lowest nitrogen content of 1.2575%. The results showed that there was a significant interaction between the levels of humic and fulvic acid and the cultivars, the combination (T4 × Kaws cultivar) gave the highest percentage of nitrogen 1.4833% .
| V | T1 | T2 | T3 | T4 | Average |
| V1 | 1.0300 | 1.230 | 1.3200 | 1.4300 | 1.2575 |
| V2 | 1.0700 | 1.2500 | 1.3467 | 1.4667 | 1.2833 |
| V3 | 1.0967 | 1.2633 | 1.4133 | 1.4833 | 1.3142 |
| V4 | 1.0800 | 1.2767 | 1.3500 | 1.4500 | 1.2892 |
| Average | 1.0700 | 1.2567 | 1.3583 | 1.4592 | |
Protein %
Table 7 showed that there were significant differences between the levels of humic and fulvic acid, and between cultivars, and the interaction between them in protein %.
Table 7 showed a significant superiority of humic and fulvic acid levels in nitrogen percentage. Where the treatment of the third level excelled 3 g gave the highest protein 9.11%, while the comparison treatment and the control gave the lowest protein 6.19%, and this is consistent with Islam and Munda that adding humic acid to the soil or spraying on the leaves led to the accumulation of nitrogen and protein in yellow corn.
Table 7 showed a significant superiority among the cultivars in the percentage of protein . Whereas, the Kaws variety was superior, as it gave 8.15%. While the Forat cultivar gave the lowest protein content of 7.56%. The results showed that there was a significant interaction between the levels of humic and fulvic acid and the cultivars, the combination (T4 × Kaws cultivar) gave the highest percentage of protein 9.27%.
| V | T1 | T2 | T3 | T4 | Average |
| V1 | 6.44 | 7.71 | 8.25 | 8.94 | 7.84 |
| V2 | 6.70 | 7.80 | 8.40 | 9.15 | 8.01 |
| V3 | 6.84 | 7.88 | 8.61 | 9.27 | 8.15 |
| V4 | 4.78 | 7.96 | 8.42 | 9.06 | 7.56 |
| Average | 6.19 | 7.84 | 8.42 | 9.11 | |
Oil %
Table 8 showed that there were significant differences between the levels of humic and fulvic acid, oil %. Table 8 showed a significant superiority of humic and fulvic acid levels in oil%. Where the treatment of the third level excelled 3 g gave the highest oil 5.321%, while the comparison treatment and the control gave the lowest oil 3.338%.
| V | T1 | T2 | T3 | T4 | Average |
| V1 | 3.093 | 4.200 | 4.627 | 5.253 | 4.293 |
| V2 | 3.140 | 4.260 | 4.723 | 5.340 | 4.366 |
| V3 | 3.207 | 4.343 | 4.720 | 5.263 | 4.383 |
| V4 | 3.913 | 3.913 | 4.733 | 5.427 | 4.497 |
| Average | 3.338 | 4.179 | 4.701 | 5.321 | |
Conclusion
The application of humic acid and fulvic acid can effectively promote increases in maize yield and improvements in quality; furthermore, combining them with suitable maize varieties maximizes these benefits. By applying humic acid and fulvic acid judiciously in maize cultivation, it is possible to achieve both high yields and superior quality.
In addition, humic acid fertilizer is an environment-friendly substance with great application value and development prospects.
How about the price of humic acid and fulvic acid, please feel free to contact Dora team.
