Perry R. Miller

Oilseed crops for semiarid cropping systems in the Northern Great Plains

oilseed crop produced in the USA, canola is the dominant oil crop in Canada. The cool climatic conditions Oilseed crops are grown throughout the semiarid region of the characteristic of the Canadian prairies provide an ideal northern Great Plains of North America for use as vegetable and industrial oils, spices, and birdfeed. In a region dominated by winter environment for Brassica spp. oilseeds and flax (Table and spring wheat (Triticum aestivum L. emend. Thell.), the accep2) while the climate found in the USA is better suited tance and production of another crop requires that it both has an to the warm season crops like soybean and sunflower. agronomic benefit to the cropping system and improve the farmers’ In the northern Great Plains, soybean is a relatively economic position. In this review, we compare the adaptation and new crop finding a place in semiarid cropping systems rotational effects of oilseed crops in the northern Great Plains. Canola with the development of early maturing, low heat–unit (Brassica sp.), mustard (B. juncea and Sinapis alba L.), and flax cultivars (Miller et al., 2002). As a result, the vast major(Linum usitatissimum L.) are well adapted to cool, short-season conity of soybean production in both the USA and Canada ditions found on the Canadian prairies and northern Great Plains occurs in wetter regions east of the Great Plains. Howborder states of the USA. Sunflower (Helianthus annuus L.) and safflower (Carthamus tinctorius L.) are better adapted to the longer ever, for the other oilseed crops listed in Table 1, the growing season and warmer temperatures found in the northern and majority of production occurs within the northern Great central Great Plains states. Examples are presented of how agronomic Plains. practices have been used to manipulate a crop’s fit into a local environDiversification within cereal-based cropping systems ment, as demonstrated with the early spring and dormant seeding can be critical to breaking pest infestations that are management of canola, and of the role of no-till seeding systems in common with monoculture (Bailey et al., 1992, 2000; allowing the establishment of small-seeded oilseed crops in semiarid Elliot and Lynch, 1995; Holtzer et al., 1996; Krupinsky regions. Continued evaluation of oilseed crops in rotation with cereals et al., 2002). Results of crop rotation studies in the Great will further expand our understanding of how they can be used to Plains revealed that where oilseeds are adapted, their strengthen the biological, economic, and environmental role of the region’s cropping systems. Specific research needs for each oilseed inclusion in rotation with cereals could increase net recrop have been recommended. turns and reduce risk through improved production stability (Lafond et al., 1993; Dhuyvetter et al., 1996; Zentner et al., 2002). In addition, the yield of wheat was increased when following oilseeds in rotation, confirmO crops are grown throughout the semiarid region of the northern Great Plains of North ing that monoculture systems are the least effective America for use as vegetable and industrial oils, spices, means of optimizing wheat production (Lafond et al., and birdfeed. In a region dominated by winter and 1992; Brandt and Zentner, 1995; Anderson et al., 1999). spring wheat (Triticum aestivum L.), the acceptance and The use of minimum and no-till seeding systems has production of another crop requires that it both has an been found to provide an effective means of controlling agronomic benefit to the cropping system and improves soil erosion in various regions of the Great Plains (Black the farmers’ economic position. Given that most oilseed and Power, 1965; Lindwall and Anderson, 1981). Imcrops have an indeterminate growth habit, adaptation provements in seed yield with conservation tillage have is influenced by tolerance to high temperature and been reported as a result of increased levels of plantdrought stress and by crop management to take advanavailable water throughout the soil profile in the spring tage of optimum environmental conditions for flowering (Aase and Reitz, 1989; Brandt, 1992; Lafond et al., 1992) and seed fill. The increasing area of oilseed crop producand increased water use efficiency due to favorable mition is an indication of the success of plant breeders croclimate conditions created by standing stubble (Cutand agronomists in developing suitable cultivars and forth and McConkey, 1997). Some oilseed crops are production methods in this semiarid region (Table 1). small seeded, requiring good surface soil moisture for While soybean [Glycine max (L.) Merr.] is the major seed germination and crop establishment, as is effectively provided in direct-seeding systems in the northern A.M. Johnston, Potash and Phosphate Inst. of Canada, 12-425 PineGreat Plains. As a result, adoption of conservation tillhouse Dr., Saskatoon, SK, Canada S7K 5K2; D.L. Tanaka, USDAage management not only reduces soil loss by erosion, ARS, Northern Great Plains Res. Lab., Box 459, Mandan, ND 58554; but also can facilitate extending the crop rotation and P.R. Miller, Montana State Univ., Dep. of Land Resour. and Environ. Sci., P.O. Box 173120, Bozeman, MT 59717-3120; S.A. Brandt, Agric. allowing for diversification of the crops grown. Ecoand Agri-Food Can., Box 10, Scott, SK, Canada S0K 4A0; D.C. Nielnomic success with a diversified crop rotation has been sen, USDA-ARS, Cent. Great Plains Res. Stn., 40335 Country Rd. reported to be improved with the implementation of GG, Akron, CO 80720; G.P. Lafond, Agric. and Agri-Food Can., Box conservation tillage practices, such as minimum and zero760, Indian Head, SK, Canada S0G 2K0; and N.R. Riveland, North Dakota State Univ., Williston Res. Ext. Cent., 14120 Hwy. 2, Williston, tillage (Lafond et al., 1993; Rossetti et al., 1999; Zentner ND 58101-8629. Saskatoon Res. Cent. Publ. 1421. Received 1 Dec. et al., 2002). 2000. *Corresponding author (ajohnston@ppi-ppic.org). The objective of this review is to summarize information on the adaptation and production potential of some Published in Agron. J. 94:231–240 (2002).

Response of three Brassica species to high temperature stress during reproductive growth.

The effect of short periods of high temperature stress on the reproductive development and yield of three Brassica species were studied in a growth chamber experiment conducted for 2 yr. Two genotypes from Brassica juncea L. and one each from B. napus L. and B. rapa L. were grown under day/night temperatures of 20/15 °C till early flowering or early pod development, subjected to high temperature stress of 28/15 °C or 35/15 °C for 7 d and then allowed to recover at 20/15 °C. Species differed in optimum temperatures, with B. juncea and B. rapa having higher optimum temperature than B. napus. Dry matter was unaffected by moderate temperature stress, while it was reduced by high temperature stress. The 35/15 °C treatment was injurious to reproductive organs at different developmental stages of all three species. High temperatures at flowering affected yield formation more than high temperature at pod development. On the main stem, mean seed yield reduction due to heat stress was 89%, but partial compensation ...

In Search of a Sustainable Cropping System for the Semiarid Canadian Prairies

ABSTRACT Producers in the semiarid Canadian prairies have begun to extend and diversify their cropping systems. These newer cropping systems are often considered to be more sustainable. We examine the agronomic, environmental, and economic effects of reducing summerfallow use and including grain lentil (Lens culinaris Medikus) in rotation with spring wheat (Triticum aestivum L.). Data from a long-term crop rotation experiment conducted on a medium texture soil at Swift Current, Saskatchewan were analyzed. Four cropping systems were evaluated over the 1979 to 1997 period; namely, fallow-wheat (F-W), fallow-wheat-wheat (F-W-W), continuous wheat (W), and wheat-lentil (W-L). Nitrate leaching below the 120 cm rooting depth of wheat was lower under continuously cropped systems than under fallow-based rotations, and was lowest overall for W-L. Wheat, whether grown on fallow or stubble, used almost all of the available water in the 0–120 cm depth soil profile, but lentil extracted about 1.5 cm less water than wheat. On average, wheat yield was unaffected by inclusion of lentil in the rotation; however, grain protein content was higher in 11 of 18 years. The incidence of leaf spotting diseases in wheat was lowest for wheat grown after lentil and highest for wheat grown on fallow. Soil quality (soil organic carbon, mineralizable N and C, light fraction organic C, and water stable aggregates) increased with cropping intensity in the order of W-L ≥ W > F-W-W > F-W. Although inputs of non-renewable energy and CO2 emissions were higher for the continuous compared to fallow-based rotations, including lentil in the rotation lowered the energy requirements for N fertilizer and provided an overall 19% reduction in CO2 emissions. The economics favored the W-L system whenever lentil price was above

Cropping sequence affects wheat productivity on the semiarid northern Great Plains

350 t−1. The level of financial risk was lowest for F-W and F-W-W, intermediate for W-L, and highest for W. Our findings confirm the recent changes in land use practices being adopted by producers, and clearly show that extending and diversifying crop rotations by reducing fallow and including pulse crops in the rotation will improve the overall sustainability of agricultural production in this semiarid region.

Yield and water use efficiency of pulses seeded directly into standing stubble in the semiarid Canadian Prairie

Extension of the commonly used spring wheat (Triticum aestivum L.)-fallow rotation to include broadleaf crops requires information on their effects on a following wheat crop. We grew a spring wheat test crop on the stubbles of wheat and seven broadleaf crops: desi chickpea (Cicer arietinum L.), dry bean (Phaseolus vulgaris L.), dry pea (Pisum sativum L.), lentil (Lens culinaris L.), mustard (Brassica juncea L.), safflower (Carthamus tinctorius L.), and sunflower (Helianthus annuus L.). This study was conducted near Swift Current, SK, from 1993 to 1997, and Congress, SK, from 1995 to 1997. After harvest, soil water differed among crop stubbles and by sampling depth. To the 60-cm depth, only soil under dry bean stubble held more water (8 mm), while soil under lentil, desi chickpea, sunflower and safflower stubbles held less water (6, 8, 9 and 17 mm, respectively) than wheat stubble (P < 0.05). From 60 to 120 cm, soil under dry pea and dry bean held more water (7 and 10 mm, respectively), and under sunflower...

Optimum plant population density for chickpea and dry pea in a semiarid environment

In semiarid climates, appropriate management of the previous crop stubble in combination with seeding method is important to improve growing conditions for the subsequent crop. To determine the effects of standing stubble of various heights on the microclimate and on the growth and yield of pulse crops, we seeded desi chickpea (Cicer arietinum L. “Cheston”), field pea (Pisum sativum L. “Grande”), and lentil (Lens culinaris L. “Laird”) directly into cultivated, short (15 to 18 cm), and tall (25 to 36 cm) spring wheat (Triticum aestivum L.) stubble. Standing stubble changed the microclimate near the soil surface by reducing soil temperatures, solar radiation, wind speed, and potential evapotranspiration throughout the life cycle of these crops. Microclimate effects were much more pronounced for tall versus short stubble. The three pulses responded similarly to increasing stubble height. Vine length increased as stubble height increased, but the plants did not stand more erect. However, there was a tendency ...

The adaptation of seven broadleaf crops to the dry semiarid prairie

Chickpea (Cicer arietinum L.), an annual grain legume, is being broadly included in cereal-based cropping systems throughout the semiarid Canadian prairies, but information on optimum plant population density (PPD) has not been developed for this region. This study, which was conducted from 1998 to 2000 in southwestern Saskatchewan, determined the effect of PPD on field emergence, seed yield and quality, and harvestability of kabuli and desi chickpea compared with dry pea (Pisum sativum L.). Seed yields of all legumes increased with increasing PPD when the crops were grown on conventional summerfallow. The PPD that produced the highest seed yields ranged from 40 to 45 plants m-2 for kabuli chickpea, from 45 to 50 plants m-2 for desi chickpea, and from 75 to 80 plants m-2 for dry pea. When the legumes were grown on wheat stubble, the PPD that gained optimum seed yield ranged from 35 to 40 plants m-2 for kabuli chickpea, from 40 to 45 plants m-2 for desi chickpea, and from 65 to 70 plants m-2 for dry pea. T...

Object-oriented crop classification using multitemporal ETM+ SLC-off imagery and random forest

To develop diversified cropping systems for the dry semiarid prairie, the adaptation of alternative crops must be known. This experiment compared the adaptation of seven pulse and oilseed crops—desi chickpea (Cicer arietinum L.), dry bean (Phaseolus vulgaris L.), dry pea (Pisum sativum L.), lentil (Lens culinaris L.), mustard (Brassica juncea L.), safflower (Carthamus tinctorius L.), and sunflower (Helianthus annuus L.) — with spring wheat (Triticum aestivum L.), using two tillage practices — no-till and minimum tillage, including both fallow and wheat stubble-field phases. It was conducted near Swift Current, SK 1992–1996, and on a commercial farm near Congress, SK 1994–1995. Tillage system had no consistent effect on plant densities, which were generally adequate. Mustard, desi chickpea, dry pea and lentil required fewer degree days (5°C base) to reach anthesis, compared with wheat, while safflower and sunflower required more than wheat. Dry pea generally matured sooner than wheat, while lentil and must...

Adaptation of alternative pulse and oilseed crops to the semiarid Canadian Prairie: Seed yield and water use efficiency

The utility of Enhanced Thematic Mapper Plus (ETM+) has been diminished since the 2003 scan-line corrector (SLC) failure. Uncorrected images have data gaps of approximately 22% and gap-filling schemes have been developed to improve their usability. We present a method to classify a northeast Montana agricultural landscape using ETM+ SLC-off imagery without gap-filling. We use multitemporal data analysis and employ an object-oriented approach to define objects, agricultural fields, with cadastral data. This approach was assessed by comparison to a pixel-based approach. Results indicate that an ETM+ SLC-off image can be classified with better than 85% overall accuracy without gap-filling.

Seedling emergence, pod development, and seed yields of chickpea and dry pea in a semiarid environment

Diversification and intensification of the cropping systems in the traditional wheat-fallow area of the semiarid Canadian prairie is necessary to improve sustainability. Selection of alternate crops to include in cropping systems requires information on production risks with different climate regimes. To understand water use/yield relationships of alternate crops, three pulse crops (leguminous grain crops) [chickpea (Cicer arietinum L.), pea (Pisum sativum L.) and lentil (Lens culinaris Medik.)], three oilseed crops [canola (Brassica napus L. and B. rapa L.) and mustard (B. juncea L.)], and one cereal crop [wheat (Triticum aestivum L.)] were studied under varying water regimes: during 1996–1998 under well-watered, rainfed, imposed drought conditions, and in 2001 under rainfed conditions. Generally, the relative ranking between crops for water use was maintained across water regimes, such that the crops separated into three general groups of water users (high: wheat, B. napus, mustard; medium: chickpea, B....