Silage-Crop Vegetative Mass Yields and Nutrition

Surveys were carried out in Moscow oblast to estimate the green forage nutritional value and the yield performance of sunflower, sweet sorghum, and corn hybrids split into different maturity groups with the comparison approach. The crop yields and chemical composition of vegetative mass of the crops listed above were determined. All the experimental silage crops are characterized by high yields of vegetative mass. In corn, for instance, it increases along with increasing the value for the condition early maturity index (FAO) from 374 centners/ha in early maturity hybrids to 486 centners/ha in medium maturity hybrid plants. The highest value for this index, comprising 491 centers/ha, was recorded in sweet sorghum. The sunflower vegetative mass made up 442 centners/ha. An increase in the plant cutting height when harvesting mid-early hybrids reduces the vegetative mass yield by 10%, while it tends to increase the green-forage energy value from 2.08 to 2.41 MJ ME. Harvesting mid-early maturity hybrids after the first frost strikes contributes to a slight increase in the nutrient content of natural feeds (from 1.87 to 2.00 MJ ME), reducing the energy concentration in dry matter from 9.74 to 9.48 MJ ME. Sweet sorghum in terms of the nutrient yield per ha and the energy concentration in the silage dry matter is not inferior to the corn. With respect to the protein yield per ha, it is characterized by the highest value for this indicator, comprising 1028 kg. However, the natural sweet-sorghum feed is inferior to the natural corn feed in terms of the energy value (1.86 MJ ME). Sunflower is different in the low green-forage nutrient content (1.53 MJ ME) and the least metabolizable energy per ha (67.6 vs. 90.9 GJ for medium-maturity corn hybrids) because of high humidity.