Interseeded pennycress and camelina yield and influence on row crops

Abstract

Field pennycress (Thlaspi arvense L.) (PC) and winter camelina [Camelina sativa (L.) Crantz] (WC) have the potential to provide ecosystem services and economic incentives when adopted as an oilseed cover crops in corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] rotations. However, PC and WC establishment and yield in the northern Corn Belt and their subsequent impact on row crops are not well known.This study was conducted to determine the effects of interseeding dates (R4, R5, and R6; and R6, R7, and R8 development stages for corn and soybean, respectively) and cover crop species (PC, WC, and winter rye [Secale cereale L.]) on seed yield and oil content of interseeded oilseeds (PC and WC) and relay soybean, and 3rd-year corn grain yield and quality. Study sites were initiated near Ames, IA; Morris and Rosemount, MN; and Prosper, ND. Late interseeding of PC and WC resulted in greater oilseed yield. Overall yields of PC (218-880 kg ha -1 ) and WC (15-770 kg ha -1 ), averaged across interseeding dates, were low when interseeded in corn and soybean. The PC and WC reduced relay-soybean grain yield by 13-32% and 13-42%, respectively. Corn grain yield and quality following relay soybean were not affected by the residual effects of oilseed cover crops. Based on the results of our study, we do not recommend relay cropping soybean with PC and WC in the upper Midwest. INTRODUCTIONCorn (Zea mays L.)-soybean [Glycine max (L.) Merr.] rotation with winter fallow forms the predominant cropping system in the midwestern United States

Environmental trade-offs of relay-cropping winter cover crops with soybean in a maize-soybean cropping system

“…Berti et al (2015) reported 47% and 71% soybean seed yield reduction in Morris and Prosper, respectively, in relay cropping with camelina compared with sole soybean planted at the normal seeding date. However, in contrast to some studies reporting soybean yield losses offset by camelina seed yield (Gesch et al 2014;Johnson et al 2017Johnson et al , 2015Ott et al 2019), in our study soybean seed yield losses were not offset by the winter crops seed yield (Patel et al 2021), causing a lower net margin. A very limited or even negligible impact of the cover crop on the main crop yield is often reported in literature, mainly because the cover crop is interseeded after the weed free critical period of the main cash crop has passed (Snapp et al 2005).…”

Desiccation of corn allows earlier direct seeding of winter camelina in the northern Corn Belt

“…Additionally, camelina oil in the present study (385 g kg −1 average) was much greater than that in the Patel et al. (2021) study which averaged 315 g kg −1 when following corn. These authors attributed low camelina productivity under such interseeded systems to stress and growth suppression caused by a combination of lack of light during seedling development under the corn canopy followed by residue that covered the plants following grain harvest.…”

“…This yield is approximately four-times greater than the overall yield reported for winter camelina interseeded into standing corn across three different seeding dates (R4, 5, and 6 stages of corn) over four locations spanning south and western Minnesota, eastern North Dakota, and central Iowa (Patel et al, 2021). Additionally, camelina oil in the present study (385 g kg −1 average) was much greater than that in the Patel et al (2021) study which averaged 315 g kg −1 when following corn. These authors attributed low camelina productivity under such interseeded systems to stress and growth suppression caused by a combination of lack of light during seedling development under the corn canopy followed by residue that covered the plants following grain harvest.…”

“…Across locations and treatments, winter camelina in the present study yielded 815 kg ha −1 with higher yields in Morris than Rosemount. This yield is approximately four‐times greater than the overall yield reported for winter camelina interseeded into standing corn across three different seeding dates (R4, 5, and 6 stages of corn) over four locations spanning south and western Minnesota, eastern North Dakota, and central Iowa (Patel et al., 2021). Additionally, camelina oil in the present study (385 g kg −1 average) was much greater than that in the Patel et al.…”

“…However, this study also demonstrated reduced winter survival and spring cover of camelina due to competition for light during early emergence and growth. Furthermore, results indicated that corn residue that covered seedlings after harvest also likely suppressed growth, which led to low seed yields when used in a relay system with soybean (Patel et al., 2021). If winter camelina is intended to be harvested for seed, it must also be considered that planting it too early can result in lower yields (Gesch & Cermak, 2011).…”