Brett Allen - Academia.edu (original) (raw)
Papers by Brett Allen
<p>Renewable bioenergy feedstocks offset the demand for conventional petrol... more <p>Renewable bioenergy feedstocks offset the demand for conventional petroleum-based energy resources. Switchgrass (Panicum virgatum L.) is a warm-season perennial C4 grass that has been utilized for lingo-cellulosic ethanol production and direct energy via combustion. However, little is known about its potential as a feedstock in the semi-arid northern Great Plains USA, including the impact of N fertilizer application on biomass production and on environmental quality. A field study initiated in 2009 seeded ‘Sunburst’ switchgrass into 12.2 m by 30.5 m plots. Split plots randomized within each main plot included fertilizer N broadcast each spring at 0, 28, 56, and 84 kg N per ha as urea, with four treatment replicates. Aboveground biomass, allowing a 20 cm stubble height, was harvested, weighed, and dried at 55 deg C each fall beginning in 2011 from four randomly selected 0.25 m sq areas. Soil cores were taken to a depth of 1.2 m in fall 2018, air-dried, and analyzed for soil nitrate. Switchgrass biomass ranged from 1.8 to 12.3 Mg per ha. In most years, N application increased switchgrass biomass, but response to N rates above 28 kg per ha was inconsistent. Biomass from fertilized switchgrass averaged 6.5 Mg per ha compared to 4.4 Mg per ha for the unfertilized control.  Soil nitrate levels indicated the potential of (over)fertilization of switchgrass feedstocks to impact water resources in semi-arid environments.</p>
Field Crops Research, 2017
Agriculture, Ecosystems & Environment, 2016
Field Crops Research, 2012
Available water and N fertility are primary constraints to crop production in the northern Great ... more Available water and N fertility are primary constraints to crop production in the northern Great Plains of the USA. A field trial was initiated in 2004 to compare four crop rotations in a complete factorial of two tillage and two management systems. Rotations were continuous spring wheat (SW), pea-SW, barley hay-pea-SW, and barley hay-corn-pea-SW. Tillage systems were no till and field cultivator tillage, while management systems were conventional and ecological. Conventional management included broadcast nitrogen fertilizer, standard seeding rates, and short stubble height. Ecological management practices varied by crop, and included banded nitrogen fertilizer for cereals, increased seeding rate, delayed planting date for SW, and taller stubble height. Continuous SW grain yield was 26% lower than SW in more diverse rotations. Pea grain yield was 18% lower in 2-yr rotations than in more diverse rotations. Ecologically managed SW yielded 29% less than conventionally managed SW, presu...
<p>... more <p>Better management practices have been used to increase soil water storage and reduce evaporation from the soil surface to optimize crop water use efficiency (WUE) in irrigated agriculture. A field study was conducted to evaluate the effect of  conventional tillage (CT), No-till (NT) and strip tillage (ST) practices on yield, water use (WU) and WUE of sugarbeet (Beta vulgaris L.) on a clay loam soil under over-head sprinkler irrigation system in the northern Great Plains. Tillage treatments were replicated five times in a randomized block design. Seasonal WU and WUE for sugarbeet root and sucrose yield were determined for the 2018 and 2019 growing seasons according to the water balance and WUE equations under three tillage practices. Results showed that no significant differences due to tillage treatment were found for crop WU, root yield, sucrose yield, and WUE for sugarbeet root and sucrose in 2018 and 2019 growing seasons. In 2019, the average value of WU across three tillage systems (616 mm) was significantly greater relative to 2018 (468 mm) due to atypical large rainfalls (218mm) occurred in September of 2019. Consequently, WUE values for both root and sucrose yield in 2019 under CT, NT, and ST were significantly greater than those in 2018. While NT and ST practices are promising alternative to CT for agricultural production in this region, further research is needed prior to making any recommendation.</p>
Heliyon, 2017
Information on the long-term effect of management practices on soil C and N stocks is lacking. An... more Information on the long-term effect of management practices on soil C and N stocks is lacking. An experiment was conducted from 2004 to 2011 in the northern Great Plains, USA to examine the effects of tillage, crop rotation, and cultural practice on annualized crop residue (stems + leaves) returned to the soil and grain yield, and soil total C (STC) and total N (STN) stocks at the 0-120 cm depth. Tillage practices were no-tillage (NT) and conventional tillage (CT) and crop rotations were continuous spring wheat ( L.) (CW), spring wheat-pea ( L.) (W-P), spring wheat-barley ( L.) hay-pea (W-B-P), and spring wheat-barley hay-corn ( L.)-pea (W-B-C-P). Cultural practices were traditional (conventional seed rates and plant spacing, conventional planting date, broadcast N fertilization, and reduced stubble height) and improved (variable seed rates and plant spacing, delayed planting, banded N fertilization, and increased stubble height). Crop residue and grain yield were greater with CW an...
Journal of Environmental Protection, 2016
Efforts have increased to measure nitrate losses from farmland under different management practic... more Efforts have increased to measure nitrate losses from farmland under different management practices due to environmental and public concerns over levels of nitrate-nitrogen (NO 3-N) in surface and ground waters. This study evaluated the effect of conventional tillage (CT) and strip tillage (ST) practices and three N application rates on NO 3-N concentrations in soil water at a 76 cm depth under irrigated sugar-beet (Beta vulgaris L.) in a clay loam soil. Nitrogen rates were applied as dry urea at 120, 150, 180 kg N ha −1 in 2006; 130, 160, 190 kg N ha −1 in 2007; and 110, 140, 170 kg N ha −1 in 2008. Soil water volumes were measured weekly during each growing season using three ceramic suction cup samplers per plot placed at a 76 cm depth below the soil surface under each tillage. Results indicated that NO 3-N concentrations at the 76 cm depth in the soil profile were not significantly affected by either tillage practice or by N application rate due to soil variability across the fi...
Industrial Crops and Products, 2016
Industrial Crops and Products, 2015
Crucifer oilseeds as renewable biofuels feedstock could offset demand for petroleum-based alterna... more Crucifer oilseeds as renewable biofuels feedstock could offset demand for petroleum-based alternatives. Current knowledge is limited regarding crop yield potential and N management in semi-arid cropping systems. In NE Montana, a 5-yr study considered no-till production of durum (Triticum durum Desf.) in rotation with oilseed crucifers camelina [Camelina sativa (L.) Crantz], crambe (Crambe abyssinica Hochst. ex R.E. Fries), and Brassica juncea L. canola, with durum-chemical fallow as the control. The N use efficiency was significantly related to seed yield in the three crucifer oilseeds and that juncea canola typically utilized N more efficiently than crambe and camelina. Similarly, N use efficiency was significantly related to grain yield in durum following oilseeds. Yield of durum following juncea canola was as great as that for durum following fallow and greater than that for durum following camelina or crambe. Durum following camelina, juncea canola, or fallow used N more efficie...
Lack of diversification constrains dryland spring wheat (Triticum aestivum L.) production in the ... more Lack of diversification constrains dryland spring wheat (Triticum aestivum L.) production in the northern Great Plains. We initiated a field study in 2004 comparing four crop rotations with each component present in a two-by-two matrix of tillage (conventional vs. zero tillage) and management (conventional vs. ecological) systems. Rotations were continuous spring wheat (SW), SW-pea, SW-barley hay-pea, and SW-barley hay-corn-pea. Ecological management practices varied by crop and were designed to improve snow capture and competitiveness with weeds. Tillage system rarely influenced SW production. Conversely, rotation and management system interacted with years. Over six years, SW in diversified rotations typically had greater soil water content at planting, resulting in greater water use and 473 kg ha-1 additional grain yield than continuous SW. Conversely, ecologically managed SW averaged 644 kg ha-1 less yield than conventionally managed SW. Diversified rotations improved SW yield u...
Diversification of continuous durum system can improve economic and environmental sustainability ... more Diversification of continuous durum system can improve economic and environmental sustainability in semiarid cropping systems, but little is known about the influence of rotation type and management system on durum performance. We conducted a study from 2005 to 2011 comparing two sets of crops in stacked (durum-durum-canola-pea and durum-durum-flax-pea) and alternate-year (durum-canola-durum-pea and durum-flax-durum-pea) rotations under conventional and ecological management levels on durum yield and characteristics. Continuous durum was included as a control. Conventional management included preplant tillage, broadcast urea, standard seeding rates, and short durum residue height. Ecological management included zero tillage, banded urea at planting, greater seeding rates, and tall durum residue height. Average durum grain yield, plant height, and plant stand across years were lower in durum-durum-canola-pea than other rotations under the conventional but not under the ecological man...
<p>Renewable bioenergy feedstocks offset the demand for conventional petrol... more <p>Renewable bioenergy feedstocks offset the demand for conventional petroleum-based energy resources. Switchgrass (Panicum virgatum L.) is a warm-season perennial C4 grass that has been utilized for lingo-cellulosic ethanol production and direct energy via combustion. However, little is known about its potential as a feedstock in the semi-arid northern Great Plains USA, including the impact of N fertilizer application on biomass production and on environmental quality. A field study initiated in 2009 seeded ‘Sunburst’ switchgrass into 12.2 m by 30.5 m plots. Split plots randomized within each main plot included fertilizer N broadcast each spring at 0, 28, 56, and 84 kg N per ha as urea, with four treatment replicates. Aboveground biomass, allowing a 20 cm stubble height, was harvested, weighed, and dried at 55 deg C each fall beginning in 2011 from four randomly selected 0.25 m sq areas. Soil cores were taken to a depth of 1.2 m in fall 2018, air-dried, and analyzed for soil nitrate. Switchgrass biomass ranged from 1.8 to 12.3 Mg per ha. In most years, N application increased switchgrass biomass, but response to N rates above 28 kg per ha was inconsistent. Biomass from fertilized switchgrass averaged 6.5 Mg per ha compared to 4.4 Mg per ha for the unfertilized control.  Soil nitrate levels indicated the potential of (over)fertilization of switchgrass feedstocks to impact water resources in semi-arid environments.</p>
Field Crops Research, 2017
Agriculture, Ecosystems & Environment, 2016
Field Crops Research, 2012
Available water and N fertility are primary constraints to crop production in the northern Great ... more Available water and N fertility are primary constraints to crop production in the northern Great Plains of the USA. A field trial was initiated in 2004 to compare four crop rotations in a complete factorial of two tillage and two management systems. Rotations were continuous spring wheat (SW), pea-SW, barley hay-pea-SW, and barley hay-corn-pea-SW. Tillage systems were no till and field cultivator tillage, while management systems were conventional and ecological. Conventional management included broadcast nitrogen fertilizer, standard seeding rates, and short stubble height. Ecological management practices varied by crop, and included banded nitrogen fertilizer for cereals, increased seeding rate, delayed planting date for SW, and taller stubble height. Continuous SW grain yield was 26% lower than SW in more diverse rotations. Pea grain yield was 18% lower in 2-yr rotations than in more diverse rotations. Ecologically managed SW yielded 29% less than conventionally managed SW, presu...
<p>... more <p>Better management practices have been used to increase soil water storage and reduce evaporation from the soil surface to optimize crop water use efficiency (WUE) in irrigated agriculture. A field study was conducted to evaluate the effect of  conventional tillage (CT), No-till (NT) and strip tillage (ST) practices on yield, water use (WU) and WUE of sugarbeet (Beta vulgaris L.) on a clay loam soil under over-head sprinkler irrigation system in the northern Great Plains. Tillage treatments were replicated five times in a randomized block design. Seasonal WU and WUE for sugarbeet root and sucrose yield were determined for the 2018 and 2019 growing seasons according to the water balance and WUE equations under three tillage practices. Results showed that no significant differences due to tillage treatment were found for crop WU, root yield, sucrose yield, and WUE for sugarbeet root and sucrose in 2018 and 2019 growing seasons. In 2019, the average value of WU across three tillage systems (616 mm) was significantly greater relative to 2018 (468 mm) due to atypical large rainfalls (218mm) occurred in September of 2019. Consequently, WUE values for both root and sucrose yield in 2019 under CT, NT, and ST were significantly greater than those in 2018. While NT and ST practices are promising alternative to CT for agricultural production in this region, further research is needed prior to making any recommendation.</p>
Heliyon, 2017
Information on the long-term effect of management practices on soil C and N stocks is lacking. An... more Information on the long-term effect of management practices on soil C and N stocks is lacking. An experiment was conducted from 2004 to 2011 in the northern Great Plains, USA to examine the effects of tillage, crop rotation, and cultural practice on annualized crop residue (stems + leaves) returned to the soil and grain yield, and soil total C (STC) and total N (STN) stocks at the 0-120 cm depth. Tillage practices were no-tillage (NT) and conventional tillage (CT) and crop rotations were continuous spring wheat ( L.) (CW), spring wheat-pea ( L.) (W-P), spring wheat-barley ( L.) hay-pea (W-B-P), and spring wheat-barley hay-corn ( L.)-pea (W-B-C-P). Cultural practices were traditional (conventional seed rates and plant spacing, conventional planting date, broadcast N fertilization, and reduced stubble height) and improved (variable seed rates and plant spacing, delayed planting, banded N fertilization, and increased stubble height). Crop residue and grain yield were greater with CW an...
Journal of Environmental Protection, 2016
Efforts have increased to measure nitrate losses from farmland under different management practic... more Efforts have increased to measure nitrate losses from farmland under different management practices due to environmental and public concerns over levels of nitrate-nitrogen (NO 3-N) in surface and ground waters. This study evaluated the effect of conventional tillage (CT) and strip tillage (ST) practices and three N application rates on NO 3-N concentrations in soil water at a 76 cm depth under irrigated sugar-beet (Beta vulgaris L.) in a clay loam soil. Nitrogen rates were applied as dry urea at 120, 150, 180 kg N ha −1 in 2006; 130, 160, 190 kg N ha −1 in 2007; and 110, 140, 170 kg N ha −1 in 2008. Soil water volumes were measured weekly during each growing season using three ceramic suction cup samplers per plot placed at a 76 cm depth below the soil surface under each tillage. Results indicated that NO 3-N concentrations at the 76 cm depth in the soil profile were not significantly affected by either tillage practice or by N application rate due to soil variability across the fi...
Industrial Crops and Products, 2016
Industrial Crops and Products, 2015
Crucifer oilseeds as renewable biofuels feedstock could offset demand for petroleum-based alterna... more Crucifer oilseeds as renewable biofuels feedstock could offset demand for petroleum-based alternatives. Current knowledge is limited regarding crop yield potential and N management in semi-arid cropping systems. In NE Montana, a 5-yr study considered no-till production of durum (Triticum durum Desf.) in rotation with oilseed crucifers camelina [Camelina sativa (L.) Crantz], crambe (Crambe abyssinica Hochst. ex R.E. Fries), and Brassica juncea L. canola, with durum-chemical fallow as the control. The N use efficiency was significantly related to seed yield in the three crucifer oilseeds and that juncea canola typically utilized N more efficiently than crambe and camelina. Similarly, N use efficiency was significantly related to grain yield in durum following oilseeds. Yield of durum following juncea canola was as great as that for durum following fallow and greater than that for durum following camelina or crambe. Durum following camelina, juncea canola, or fallow used N more efficie...
Lack of diversification constrains dryland spring wheat (Triticum aestivum L.) production in the ... more Lack of diversification constrains dryland spring wheat (Triticum aestivum L.) production in the northern Great Plains. We initiated a field study in 2004 comparing four crop rotations with each component present in a two-by-two matrix of tillage (conventional vs. zero tillage) and management (conventional vs. ecological) systems. Rotations were continuous spring wheat (SW), SW-pea, SW-barley hay-pea, and SW-barley hay-corn-pea. Ecological management practices varied by crop and were designed to improve snow capture and competitiveness with weeds. Tillage system rarely influenced SW production. Conversely, rotation and management system interacted with years. Over six years, SW in diversified rotations typically had greater soil water content at planting, resulting in greater water use and 473 kg ha-1 additional grain yield than continuous SW. Conversely, ecologically managed SW averaged 644 kg ha-1 less yield than conventionally managed SW. Diversified rotations improved SW yield u...
Diversification of continuous durum system can improve economic and environmental sustainability ... more Diversification of continuous durum system can improve economic and environmental sustainability in semiarid cropping systems, but little is known about the influence of rotation type and management system on durum performance. We conducted a study from 2005 to 2011 comparing two sets of crops in stacked (durum-durum-canola-pea and durum-durum-flax-pea) and alternate-year (durum-canola-durum-pea and durum-flax-durum-pea) rotations under conventional and ecological management levels on durum yield and characteristics. Continuous durum was included as a control. Conventional management included preplant tillage, broadcast urea, standard seeding rates, and short durum residue height. Ecological management included zero tillage, banded urea at planting, greater seeding rates, and tall durum residue height. Average durum grain yield, plant height, and plant stand across years were lower in durum-durum-canola-pea than other rotations under the conventional but not under the ecological man...