Root mass for oilseed and pulse crops: Growth and distribution in the soil profile

Canadian Journal of Plant Science - Tập 89 Số 5 - Trang 883-893 - 2009
Yantai Gan1, C. A. Campbell2,3, H. H. Janzen4, R. Lemke5, L.P. Liu6, Prakash Basnyat1, C. L. McDonald1
1Agriculture and Agri-Food Canada, Semiarid Prairie Agricultural Research Centre, Gate #3, Airport Road E., Swift Current, Saskatchewan, Canada S9H 3X2
2Agriculture and Agri-Food Canada
3Eastern Cereal and Oilseed Research Centre, 960 Curling Ave., Ottawa, Ontario, Canada K1A 0C6;
4Agriculture and Agri-Food Canada, Lethbridge Research Centre, 5403 1st Ave S., Lethbridge, Alberta, Canada T1J 4B1
5Agriculture and Agri-Food Canada, Saskatoon Research Centre, 107 Science Place, Saskatoon, Saskatchewan, Canada S7N 0X2; and
6Department of Plant Sciences, University of Saskatchewan, 51 Campus Rd, Saskatoon, Saskatchewan, Canada S7N 1A8.

Tóm tắt

Crop roots transport water and nutrients to the plants, produce nutrients when they decompose in soil, and provide organic C to facilitate the process of C sequestration in the soil. Many studies on these subjects have been published for cereal crops, but little is known for oilseed and pulse crops. This study was conducted at Swift Current, Saskatchewan, in 2006 and 2007 to characterize the root growth and distribution profile in soil for selected oilseed and pulse crops. Three oilseed [canola (Brassica napus L.), mustard (Brassica juncea L.), flax (Linum usitatissimum L.)], three pulse crops [chickpea (Cicer arietinum L), dry pea (Pisum sativum L.) lentil (Lens culinaris Medik.)], and spring wheat (Triticum aestivum L.) were grown in 100 cm deep × 15 cm diameter lysimeters pushed into a silt loam soil. Crops were studied under rainfed and irrigated conditions. Lysimeters were removed from the field and sampled for above-ground (AG) and root mass at different depths at five growth stages. Root mass was highest for canola (1470 kg ha-1) and wheat (1311 kg ha-1), followed by mustard (893 kg ha-1) and chickpea (848 kg ha-1), and was lowest for dry pea (524 kg ha-1) and flax (440 kg ha-1). The root mass of oilseeds and pulses reached a maximum between late-flowering and late-pod stages and then decreased to maturity, while wheat root mass decreased to maturity after reaching a maximum at boot stage. On average, about 77 to 85% of the root mass was located in the 0-40 cm depth. Canola, mustard, and wheat rooted to 100 cm, while the pulses and flax had only 4 to 7% of the root mass beyond the 60 cm depth. Irrigation only increased root mass in the 0-20 cm depth. Roots developed more rapidly than AG biomass initially, but the ratio of root biomass to AG biomass decreased with plant maturity. At maturity, the ratio of root biomass to AG biomass was 0.11 for dry pea, and between 0.20 and 0.22 for the other crops tested. Our findings on rooting depths and root mass distribution in the soil profile should be useful for modelling water and nutrient uptake by crops, estimating C inputs into soil from roots, and developing diverse cropping systems with cereals, oilseeds and pulses for semiarid environments.Key words: Root growth, root biomass, rooting depth, chickpea, lentil, pea, canola, mustard, flax, root:shoot ratio

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Canadian Journal of Plant Science

Tập 89 Số 5

883-893

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