Yield, nutrient removal, and quality of sorghum grain and biomass as influenced by nitrogen and phosphorus fertilization /
| Main Author: | |
|---|---|
| Other Authors: | , , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1985.
|
| Subjects: | |
| Online Access: | Link to ProQuest copy Link to OAKTrust copy |
| Abstract: | Field experiments were conducted during 1983 and 1984 at two locations using one conventional (ATx399 x RTx430) and two high energy sorghum hybrids (Sorghum bicolor L., Moench) to evaluate the effects of N and P applications on grain, biomass, and fermentable carbohydrate production. Genotype and N most influenced grain and biomass yields at both locations. Cultivars ATx399 x RTx430 and ATx623 x RTx430 produced more grain, but less biomass than ATx623 x Rio. Applied N increased grain yields at College Station more in 1984 than in 1983, indicating a decrease in soil N after one year of total dry matter removal. Less yield response to N was observed at Weslaco. Applied P had little effect on grain or biomass production at either location. Genotype affected nutrient concentrations and partitioning, with ATx399 x RTx430 exhibiting the greatest biomass and lowest grain nutrient concentrations. This cultivar removed the least nutrients in biomass and the most through grain. Nutrient concentrations and removals in ATx623 x Rio components were the reverse of the grain hybrid. When total crop N and P removals were considered, however, no genotypic differences were observed at either location. Total crop removals of K, Ca, Mg, Fe, and Zn at College Station and K and Mg at Weslaco were influenced by genotype, with ATx623 x Rio removing the greatest quantities. Applied N increased grain and biomass concentrations and uptake of most nutrients. Increased nutrient removals generally resulted more from increases in dry matter production than from changes in nutrient concentrations. Apparent N uptake efficiency was higher at College Station (41 to 53%) than at Weslaco (24 to 37%). Complete aboveground dry matter removal of high energy sorghums resulted in an additional removal of 100 to 180 kg K and 40 to 50 kg N/ha when compared with conventional sorghum produced for grain only. Genotype influenced stalk fermentable carbohydrate yields, with ATx623 x Rio producing substantially greater amounts than the other hybrids. Applied N decreased structural carbohydrates, while nonstructural carbohydrates remained unchanged. Stalk fermentable carbohydrate yields, however, increased linearly with N application because of higher biomass yields with applied N. |
|---|---|
| Item Description: | "Major subject: Agronomy." Typescript (photocopy). Vita. |
| Physical Description: | xiv, 123 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references (leaves 119-122). |