Core Ideas Nitrogen loss in wheat production systems in Multan, Pakistan is a major problem. Biochar application with inorganic N improved wheat yield, quality, and N uptake. Biochar from poultry waste was more beneficial than biochar from green waste. Biochar was not economically profitable in the short term due to high application rates and cost. Nitrogen loss via volatilization, leaching, and surface runoff is a major problem in coarse‐textured and alkaline soils of Multan, Pakistan, impacting the economic and environmental sustainability of wheat ( Triticum aestivum L.) production systems in the region. Soil amendments with biochar in combination with optimal levels of inorganic N could improve wheat productivity, but sustainable adoption will depend on economic profitability. We evaluated the effects of biochar produced from green waste (GW‐450) and poultry waste (PW‐450) feedstock and different rates of inorganic N (0, 60, and 120 kg N ha −1 ) on wheat productivity and economic profitability. The PW‐450 improved wheat yield, quality, and nutrient uptake compared with the GW‐450, which was attributed to a lower C/N ratio and higher essential nutrients and specific surface area that enhanced adsorption properties of the former. Soil amendments with biochar in combination with inorganic N improved wheat grain yield, quality, and N uptake over non‐amended soils. On average, biochar increased wheat grain yield, protein content, and N uptake by 55 to 355 kg ha −1 , 3.7 to 6.9 g kg −1 , and 15 to 41 kg ha −1 , respectively. Despite the benefits of biochar on wheat yield, it was not economically profitable within the two growing seasons due to high application rates and price. However, the effects of biochar may last longer and potentially make biochar profitable in the long term. Overall, biochar holds promise for use in the wheat cropping system in Multan, Pakistan; further studies are recommended to better elucidate its benefit in the long term.
Modern cotton (Gossypium spp. L) cultivars are efficient in nutrient uptake and utilization, and thus, may potentially tolerate nutrient stress. Early- and late-season nutrient stress (E-stress and L-stress, respectively) effects on cotton productivity and quality were assessed under different production conditions in Camilla and Midville, GA, USA. The E-stress received no nutrient application in the early season, but the full rates were split-applied equally at the initiation of squares and the second week of bloom stages. The L-stress received 30–40% of the full nutrient rates only at the initial stage of planting. The effects of nutrient stress on cotton productivity and fiber quality were not consistent across the different production conditions. Compared to the full nutrient rate, the E-stress did not adversely impact cotton yield, but rather it improved the lint and cottonseed yields under one production condition by 17.5% and 19.3%, respectively. Averaged across all production conditions, the L-stress decreased the lint and cottonseed yields by 34.4% and 36.2%, respectively. The minimal effects of E-stress on cotton suggest nutrient rates at the early season could be reduced and more tailored rates, informed by soil and plant tissue analyses, applied shortly before the reproductive phase.
Urea is an important source of inorganic N under wheat ( Triticum aestivum L.) production system in Multan, Pakistan. However, the average N loss is high, ranging from 22 to 53% of applied N, which poses adverse environmental impacts. Reduced tillage and combined application of biochar and optimal N fertilizer could improve wheat productivity and reduce N losses. We evaluated the effects of two tillage (conventional and reduced tillage), two biochar (no biochar and poultry waste biochar), and three inorganic N rate (0, 60, and 120 kg ha −1 ) treatments on productivity and economic profitability of wheat production for two continuous growing seasons (2014–2015 and 2015–2016). Generally, reduced tillage increased wheat grain yield, protein content, and total N uptake by 0.2 Mg ha −1 , 3.0 kg kg −1 , and 37.0 kg ha −1 , respectively, when compared with conventional tillage. Biochar application increased wheat grain yield, protein content, and total N uptake by 0.3 Mg ha −1 , 6.8 kg kg −1 , and 38.6 kg ha −1 , respectively, compared with no‐biochar plots. Reduced tillage was economically profitable within the two cropping seasons, but biochar application was not, because of the high price of biochar (US$1.00 kg −1 biochar) and application rate (10 Mg biochar ha −1 ). Overall, wheat production under reduced tillage, no biochar, and the 60‐kg N ha −1 rate resulted in the greatest economic profit in this study.
Every year, the production of coal-bed natural gas in the Powder River Basin results in the discharge of large amounts of coal-bed methane water (CBMW) in Wyoming; however, no sustainable disposal methods for CBMW are currently available. A greenhouse study was conducted to evaluate the potential to use CBMW as a source of irrigation water for camelina [ (L.) Crantz]. We assessed the effects of three CBMW concentrations (0% [1:0], 50% [1:1], and 100% [0:1] tap water to CBMW) on selected soil properties, growth, seed oil, and fatty acid composition of three camelina cultivars: Blaine Creek, Ligena, and Pronghorn. The 100% CBMW reduced seed and estimated biofuel yields by 24 and 23%, respectively, but increased the oil content by 3%, relative to the control. Additionally, the 100% CBMW visibly affected soil through formation of surface crust due to elevated levels of sodium (653 mg Na kg). The 50% CBMW had no significant effects on the seed yield, estimated biofuel yield, and oil content, but the soil Na levels were still high (464 mg kg), which could pose a long-term impact on soil structure. The CBMW tended to reduce the total saturated fatty acid, but it had no significant effects on the total monounsaturated or polyunsaturated fatty acids of camelina seeds. Overall, CBMW diluted with an equal amount of good-quality water could be used to irrigate camelina in the short term. Afterward, only good-quality water would have to be used until the accumulated dissolved solids are flushed out.
Japanese cornmint, also known as menthol mint ( Mentha canadensis L. syn M. arvensis L.), is an essential oil crop cultivated in several countries in Asia and South America. The plant is currently the only commercially viable source for natural menthol as a result of the high concentration of menthol in the oil compared with other crops. The hypothesis of this study was that harvesting at regular intervals within a 24-hour period would have an effect on essential oil concentration and composition of Japanese cornmint grown at high altitude in northern Wyoming. Flowering plants were harvested every 2 hours on 7 to 8 Aug. and on 14 to 15 Aug. and the essential oil was extracted by steam distillation and analyzed by gas chromatography–mass spectroscopy (GC-MS). The effects of harvest date (Harvest 1 and Harvest 2) and harvest time (12 times within a 24-hour period) were significant on oil concentration and yield of menthol, but only harvest date was significant on the concentration of menthol in the oil. The interaction effect of harvest date and harvest time was significant on water content and on the concentrations of menthol and menthofuran in the oil and on the yield of limonene, menthol, and menthofuran. Overall, the oil concentration in grams per 100 g dried material for the two harvests (1.26 and 1.45, respectively), the concentration of menthol in the oil (67.2% and 72.9%, respectively), and menthol yield (1066 to 849 mg/100 g dried biomass) were higher in plants at Harvest 2 as compared with plants at Harvest 1. The oil concentration was higher in plants harvested at 1100 hr or at 1300 hr and lowest in the plants harvested at 1500 hr . Menthol yield was the highest in plants harvested at 1300 hr and lowest in the plants harvested at 0700 hr , 1900 hr, or at 0300 hr . This study demonstrated that harvesting time within a 24-hour period and harvest date (maturity of the crop) may affect essential oil concentration and composition of Japanese cornmint grown at high altitude in northern Wyoming.
Identifying crops that are adapted to semi-arid environments of the central and northern Great Plains (GP) has been a major challenge. An alternative crop with potential for semi-arid crop production in the GP is camelina (Camelina sativa L. Crantz). Compared to other oilseed crops, research has shown spring camelina to be cold and drought tolerant requires relatively low agricultural inputs and well adapted to semi-arid regions. Because of these agronomic attributes, camelina has been promoted as a low-input biofuel crop for the drier regions of the GP. Camelina seed has higher oil content (> 35%) with unique properties for industrial and nutritional applications. For example, a blend of camelina-based jet fuel tested in commercial and military flights in the US met all aviation fuel specifications and performance. The oil contains 40% α-linolenic acid (18:3n-6) an omega-3 fatty acid which has important implication in human and animal diets. Thus camelina has potential for commercial biofuel production and other industrial uses. However, there are limited production recommendations for camelina and the benefits and challenges of adopting camelina in cereal-based crop production systems in the GP have not been sufficiently explored. In addition, the lack of a reliable market outlet and low profitability when compared to other oilseeds are presently hampering camelina adoption by growers. Agronomic research to identify suitable camelina genotypes, seeding dates and soil fertility requirements are needed to develop site-specific production recommendations for camelina in the GP. Plant breeding efforts to develop desirable varieties with improved seed yield, oil content and fatty acids composition and tolerance to heat stress needs to be explored. Research efforts into perfecting alternative uses for camelina oil and meal such as using camelina as a drop-in product for adhesives, films, coatings, packing materials and plastics will expand the market beyond biodiesel. An expanded niche market will enhance the economic viability of camelina as a commercial oilseed in the GP.
