Winter Canola: A Potential Dual‐Purpose Crop for the United States Southern Great Plains

Abstract

Core Ideas Canola forage production was higher than wheat in fall but not in later harvests. Many of the forage quality parameters were superior in canola compared with wheat. Forage harvest decreased canola yield even before bolting but not in wheat. Canola has dual‐purpose use potential (forage and seed yield) with LF harvest. Winter canola (Brassica napus L. biennus) has the potential to be a dual‐purpose crop in the US Southern Great Plains, a region with cereal fallow mono‐cropping. However, there is little information on dual‐purpose canola in the region. Therefore, field studies were conducted in Clovis, NM, in 2013, 2014, and 2015 to compare harvesting time effect on forage productivity (dry matter), quality, and oil and seed production of canola and wheat. Harvesting time treatments were late‐fall (LF), mid‐winter (MW), early‐spring (ES), late‐spring (LS), and no‐harvest (NH). The two forage crops were canola (cv. DKW44‐10, Griffin, and Safran) and wheat (cv. TAM 111 and TAM 113). In general, crop dry matter increased and forage nutritive values decreased with delay in harvest. Dry matter of LF to ES harvests ranged from 2950 to 7740 (canola) and from 2390 to 7490 kg ha−1 (wheat), suggesting superior forage production of canola with LF to ES harvests. Crops had similar crude protein and acid detergent fiber. Canola's neutral detergent fiber was lower (238 vs. 425 g kg−1), whereas its relative feed value (188–425) was higher than wheat (127–204). Average canola seed yields (excluding 2014) were 4360, 3040, 2940, and 2720, 930 kg ha−1 with the NH, LF, MW, ES, and LS forage harvests, respectively. Forage harvest had inconsistent effects on wheat seed yield. These results show canola's potential to produce high‐quality forage and seed yield and indicate that canola can be used as a rotational break crop in the crop–livestock production systems of the Southern Great Plains.

Forage Yield and Quality of Winter Canola–Pea Mixed Cropping System

“…Moreover, the CP of canola-pea mixed cropping treatments at seeding ratios of 75:25 (7%) and 50:50 (9%) was greater than monocrop canola although the difference was not as high as that with canola-pea mixed cropping at the 25:75 seeding ratio. Similar results were reported in cereals (oat, triticale, barley) mixed with legumes (vetch, pea) where both monocrop legumes and cereal-legumes in mixture produced higher CP compared with monocrop cereals [9,15,16,24]. Monocrop pea and canola treatments had the highest values of ADF and NDF.…”

“…Canola is one of the broadleaf-type crops being explored for forage use in the US and Australia. Researchers in Australia and the US have reported comparable winter canola forage yield, but higher forage quality, compared to winter wheat [16][17][18], suggesting its potential use in intercropping/mixed cropping systems. Cereals in intercropping systems are used by legumes (e.g., pea, vetch-Vicia sativa, and lentils-Lens culinaris) as support, leading to the enhancement of light interception, above-and belowground complementary resource usage, ease of mechanical harvest of legumes, and overall improvement of yield and quality of forage and grain of both crops [3,14,19,20].…”

Winter annual alternative crops for enhanced sustainability in Iowa cropping systems

“…To improve financial stability and diversify crop rotations, winter canola has also been used as a dual-purpose crop, providing high quality forage to livestock, while producing a viable oilseed crop to be harvested (Kirkegaard et al, 2008;Sprague et al, 2014;Begna et al, 2017).…”

“…Because of the typical monoculture system, growers are experiencing challenges with pest control, reduced market availability due to grass type weeds, and reduced yields (Begna et al, 2017). Winter canola, when grazed in the late fall, provided a higher relative feed value compared to wheat, and was able to produce a viable crop for grain harvest, providing a possibility of a viable crop rotation for growers in the southern Great Plains (Begna et al, 2017). However, to maintain adequate growth recovery and oilseed yields, winter canola should only be grazed up until bud elongation (Kirkegaard et al, 2008).…”

“…Davis et al (2012) have shown that increasing cropping system diversity has a multitude of positive effects on the productivity, profitability, and ecological sustainability of Iowa's conventional corn-soybean cropping systems. Producers in the southern Great Plains and Pacific Northwest often insert winter canola into crop rotations as a break crop between winter wheat plantings Begna et al, 2017;Karow, 2014). In Iowa, corn and soybean cropping systems are prone to environmental harm; particularly topsoil erosion and nitrogen (N) losses to water resources (Qi et al, 2008;Hatfield et al, 2009;Gelder et al, 2017).…”