Due to recent classification as a commodity crop in North America, producer interest in industrial hemp (Cannabis sativa L.) has increased. In the Commonwealth of Virginia, there is a need to evaluate foreign-developed industrial hemp for its adaptability and to develop new cultivars suited to local climatic conditions. Eight cultivars (‘Bialobrzeskie’, ‘Canda’, ‘Fedora 17’, ‘Felina 32’, ‘Joey’, ‘Tygra’, ‘USO 31’, and ‘Wojko’) were evaluated for grain and five (‘Bialobrzeskie’, ‘Carmagnola’, ‘Fedora 17’, ‘Futura 75’, and ‘Wojko’) for vegetative biomass. An experiment carried out at the Virginia State Research and Demonstration (Randolph) farm was laid out in a randomized complete block design with three replications. The results show that cultivars differed in the cumulative growing degree days (CGDD) needed for growth phase transitions, with ‘USO 31’ having an early transition to the reproductive phase. In addition, ‘Fedora 17’ produced greater grain yield and may have the potential for greater performance with better management to improve its adaptability to local conditions. Across cultivars and years, the grain protein content averaged 241 g kg⁻¹ and the mineral elements were at sufficient levels for animal and human nutrition. ‘Carmagnola’ produced greater biomass yield and has the potential for adoption as local fiber cultivar.

Hemp (Cannabis sativa L.) is an annual herb from Cannabaceae family grown for its multitude of uses including fiber, seed and/or oil, and for its psychoactive ingredients. In August 2019, a hemp fa...

Soybean (Glycine max(L.) Merr.), a good source of protein and oil, is used to produce nutritious isoflavone-rich soybean-based foods. The objectives of this study were (i) to determine the germination difference among soybean seeds in various seed sizes and (ii) to evaluate effects of seed pretreatment on germination and seedling emergence. Six varieties of different seed size class were used: (i) small size (MFS-561 and V08-4773), (ii) medium size (Glen and V03-47050), and (iii) large size (MFL-159 and V07-1897). Pregermination treatments include 0, 5, or 10 hours soaking and germinating/planting with or without nitrogen fertilizer. Large seed size varieties showed low germination rate and N addition caused the least reduction in germination in these seeds during the first 24 hours. While N had no effect on seed germination after 72 hours, growth in N treated seed was low. Seedling emergence was comparable across varieties in 2013 and water priming and N application had no effect. However, while varieties did not differ in final emergence for nonprimed seeds in 2014, water priming led to a high reduction in seedling emergence of large seed varieties in this study. Application of N fertilizer had no effect on seedling emergence in field experiments.

Limited information is available about the economic benefits and costs associated with managing switchgrass (Panicum virgatum L.) produced for bioenergy feedstock in the K-deficient soils common in the southern Great Plains. The objectives of this study were to determine the most economical production system for harvesting and managing N and K fertilizations on switchgrass stands and to determine how sensitive the results are to various feedstock and fertilizer market price scenarios. A 4-year agronomic field experiment was conducted on a K-deficient site in South Central Oklahoma; the treatments included two harvest systems (summer and winter (SW) and winter only (W)), two N rates (0 and 135 kg ha⁻¹), and two K rates (0 and 67 kg ha⁻¹). Enterprise budgeting techniques and mixed ANOVA models were used to determine and compare the effects of eight harvest/N/K systems on yield, total cost, revenue, and net return. The harvest/N/K systems evaluated included SW/0/0, SW/0/67, SW/135/0, SW/135/67, W/0/0, W/0/67, W/135/0, and W/135/67. Results revealed the SW/135/67 system produced significantly (P > 0.0001) greater average yield compared to the other systems; however, the SW/0/0 system was the most (P > 0.0001) economical, realizing an average net return of $415 ha⁻¹. Compared to the base–case net return of the SW/0/0 system, the value of the additional yield generated with the SW/135/67 system was less than the costs associated with the extra nutrients and additional harvest activity. For feedstock prices greater than $110 Mg⁻¹, the most economical system shifted from the SW/0/0 to favor the SW/135/67 system.

The increasing cost of fossil-based energy sources has driven research in bio-based alternatives, such as perennial grasses for feedstock. The mid-Atlantic receives appreciable summer rainfall that may support a two-cut-per-year⁻¹ harvest. At Virginia State University, a study on annual forage sorghum and two one-year stand perennials, miscanthus, and selected switchgrass ecotypes was carried out. The experimental design was a split-plot with harvest systems and feedstock grass species randomly assigned to the main and sub-plots, respectively. Only perennial grasses were assigned to the two-cut-per-year⁻¹ system. The first cut occurred in early summer, and the second and single cut occurred after the frost-kill. Under the two-cut system, in 2022, the first-cut dry matter (DM) yield ranged from 8.9 Mg ha⁻¹ in Blackwell to 14.7 Mg ha⁻¹ in BoMaster. Additionally, except for BoMaster, the regrowth DM yields were within 10% of the first-cut DM yield. Under the one-cut system, the yield ranged from 10.8 Mg ha⁻¹ in Blackwell to 23.2 Mg ha⁻¹ in sorghum. Under the two-cut system, in 2023, miscanthus produced the greatest first-cut DM yield of 18.4 Mg ha⁻¹, while other perennials averaged 10.1 Mg ha⁻¹. Compared to the first cut, the hot and dry summer significantly reduced regrowth for all feedstock species, with the miscanthus DM yield dropping by 64%. While forage attributes differ among feedstock species, in general, both the first cut and regrowth showed greater crude protein and mineral elements, as well as lower ADF contents compared to a single cut following a killing freeze. Sorghum had better forage quality for the one-cut-per-year⁻¹ feedstock material, and, along with the first cut and regrowth, it may have the potential for use as forage for maintenance energy in animal systems. For perennials, the two-cut-per-year⁻¹ system removed the greatest quantities of nutrients during both years, with the first-cut harvest contributing about 65% of all removed N and K. Sorghum removed the greatest quantities of nutrients compared to the perennial under a one-cut-per-year⁻¹ system. Therefore, while a two-cut-per-year⁻¹ system can result in the greatest DM yields for dual-purpose use, its adoption calls for a critical analysis of economic benefits that considers feedstock bioenergy processing approaches, stand persistence, and fertilizer management strategies to address potential soil fertility depletion due to mineral element mining.