Soil Nitrogen in Response to Interseeded Cover Crops in Maize–Soybean Production Systems

Improved agronomic management strategies are needed to minimize the impact that current maize (Zea mays L.) and soybean (Glycine max (L.) Merr.) production practices have on soil erosion and nutrient losses, especially nitrogen (N). Interseeded cover crops in standing maize and soybean scavenge excess soil N and thus reduce potential N leaching and runoff. The objectives were to determine the impact that pennycress (Thlaspi arvense L.) (PC), winter camelina (Camelina sativa (L.) Crantz) (WC), and winter rye (Secale cereale L.) (WR) cover crops have on soil N, and carbon (C) and N accumulation in cover-crop biomass. The cover crops were interseeded in maize at the R5 growth stage and in soybean at R7 in four replicates over two growing seasons at four locations. Soil and aboveground biomass samples were taken in autumn and spring. Data from the maize and soybean systems were analyzed separately. The results showed that cover crops had no effect on soil NH4+-N under both systems. However, winter rye decreased soil NO3−-N up to 76% compared with no-cover-crop treatment in the soybean system. Pennycress and WC scavenged less soil N than WR. Similarly, N and C accumulation in PC and WC biomass were less than in WR, in part because of their poor growth performance under the interseeding practice. Until PC and WC varieties with improved suitability for interseeding are developed, other agronomic practices may need to be explored for improving N scavenging in maize and soybean cropping systems to reduce nutrient leaching and enhance crop diversification

Establishing winter annual cover crops by interseeding into Maize and Soybean

The limited time available for cover crop establishment after maize (Zea mays L.) and soybean [Glycine max (L.) Merr.] harvest is one of the main reasons for low cover crop adoption in the upper Midwest. Therefore, a 2‐yr multilocation study was conducted to evaluate winter annual cover crops establishment, their effect on main crop grain yields, and soil water content when interseeded into standing maize and soybean. Treatments were three interseeding dates (broadcasting at R4, R5, and R6 growth stages for maize, and R6, R7, and R8 for soybean) and three cover crops (winter camelina [WC] [Camelina sativa L.], field pennycress [PC] [Thlaspi arvense L.], winter rye [Secale cereale L.] plus a no cover crop control). Cover crop establishment and growth varied with interseeding date across locations and seasons for both maize and soybean systems. Averaged over the years, rye produced more green cover and biomass than the oilseeds in spring. However, at the northern‐most site, the greatest (40%) green cover was recorded from pennycress and indicates its potential as a cover crop. Seeding date and cover crops did not negatively affect maize or soybean grain yields or soil water content. Generally, cover crop establishment and growth were better in the soybean system than maize due to better light penetration. Further research is needed to develop better suited cultivars and/or agronomic management practices for interseeding into maize. The results of this study indicate that producers could integrate these covers to diversify and add ecosystem services to soybean production practices

Soil Nitrogen in Response to Interseeded Cover Crops in Maize–Soybean Production Systems

Improved agronomic management strategies are needed to minimize the impact that current maize (Zea mays L.) and soybean (Glycine max (L.) Merr.) production practices have on soil erosion and nutrient losses, especially nitrogen (N). Interseeded cover crops in standing maize and soybean scavenge excess soil N and thus reduce potential N leaching and runoff. The objectives were to determine the impact that pennycress (Thlaspi arvense L.) (PC), winter camelina (Camelina sativa (L.) Crantz) (WC), and winter rye (Secale cereale L.) (WR) cover crops have on soil N, and carbon (C) and N accumulation in cover-crop biomass. The cover crops were interseeded in maize at the R5 growth stage and in soybean at R7 in four replicates over two growing seasons at four locations. Soil and aboveground biomass samples were taken in autumn and spring. Data from the maize and soybean systems were analyzed separately. The results showed that cover crops had no effect on soil NH4+-N under both systems. However, winter rye decreased soil NO3−-N up to 76% compared with no-cover-crop treatment in the soybean system. Pennycress and WC scavenged less soil N than WR. Similarly, N and C accumulation in PC and WC biomass were less than in WR, in part because of their poor growth performance under the interseeding practice. Until PC and WC varieties with improved suitability for interseeding are developed, other agronomic practices may need to be explored for improving N scavenging in maize and soybean cropping systems to reduce nutrient leaching and enhance crop diversification.This article is published as Mohammed, Yesuf Assen, Swetabh Patel, Heather L. Matthees, Andrew W. Lenssen, Burton L. Johnson, M. Scott Wells, Frank Forcella, Marisol T. Berti, and Russ W. Gesch. "Soil Nitrogen in Response to Interseeded Cover Crops in Maize–Soybean Production Systems." Agronomy 10, no. 9 (2020): 1439. doi: 10.3390/agronomy10091439.</p

Establishing winter annual cover crops by interseeding into Maize and Soybean

The limited time available for cover crop establishment after maize (Zea mays L.) and soybean [Glycine max (L.) Merr.] harvest is one of the main reasons for low cover crop adoption in the upper Midwest. Therefore, a 2‐yr multilocation study was conducted to evaluate winter annual cover crops establishment, their effect on main crop grain yields, and soil water content when interseeded into standing maize and soybean. Treatments were three interseeding dates (broadcasting at R4, R5, and R6 growth stages for maize, and R6, R7, and R8 for soybean) and three cover crops (winter camelina [WC] [Camelina sativa L.], field pennycress [PC] [Thlaspi arvense L.], winter rye [Secale cereale L.] plus a no cover crop control). Cover crop establishment and growth varied with interseeding date across locations and seasons for both maize and soybean systems. Averaged over the years, rye produced more green cover and biomass than the oilseeds in spring. However, at the northern‐most site, the greatest (40%) green cover was recorded from pennycress and indicates its potential as a cover crop. Seeding date and cover crops did not negatively affect maize or soybean grain yields or soil water content. Generally, cover crop establishment and growth were better in the soybean system than maize due to better light penetration. Further research is needed to develop better suited cultivars and/or agronomic management practices for interseeding into maize. The results of this study indicate that producers could integrate these covers to diversify and add ecosystem services to soybean production practices.This article is published as Mohammed, Yesuf Assen, Heather L. Matthees, Russ W. Gesch, Swetabh Patel, Frank Forcella, Kyle Aasand, Nicholas Steffl, Burton L. Johnson, M. Scott Wells, and Andrew W. Lenssen. "Establishing winter annual cover crops by interseeding into Maize and Soybean." Agronomy Journal (2020). doi: 10.1002/agj2.20062.</p

Dry Pea (Pisum sativum L.) protein, starch and ash concentrations as affected by cultivars and environments

Dry pea (Pisum sativum L.) is an important crop in the Northern Great Plains (NGP) of the US and Canada. Information on dry pea quality as affected by cultivars and environments is limited. This experiment determined the effects of dry pea cultivars and environments on protein, starch and ash concentrations. Six dry pea cultivars (cv. Arcadia, Bridger, CDC Striker, Cruiser, Montech 4152 and SW Midas) were evaluated in randomized complete block design with four replications in 22 environments. The results showed that cultivar by environment interaction effects were highly significant on protein, starch and ash concentration (PThe accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author