Cadmium is a heavy metal present in soils from natural and anthropogenic sources. Plant uptake of Cd at levels present in the soil solution is dependent on a system that is largely metabolically mediated and competitive with the uptake system for Zn and possibly other metals. Much of the Cd taken up by plants is retained in the root, but a portion is translocated to the aerial portions of the plant and into the seed. The amount of Cd accumulated and translocated in plants varies with species and with cultivars within species. Soil, environmental and management factors impact on the amount of Cd accumulated in plants. Potential methods of reducing the accumulation of Cd in crops include reduction of Cd input to the soil system, site selection, management practices which decrease the concentration of Cd in the soil solution and its uptake and translocation by plants, and development and production of plant cultivars with the genetic tendency for low Cd uptake.

. Fertility management in canola production. Can. J. Plant Sci. 73 651-670. A review of the world literature on canola, a type of oilseed rape with low glucosinolates and low erucic acid, indicated that canola is a heavy user of plant nutrients. Canola requires as much or more nitrogen than cereal crops. Although canola requires more P than cereal crops for optimum yield, it may require lower levels of P fertilizers, as it is very effective at utilizing both soil P and apPlied P. During growttr, canola takes up large quantities of K, but only a small amount is removed in the seed, so canola appears to require less fertilizer K than cercals. Canola requires more S than do celeal crops and S deficiencies may severely restrict canola yield, particularly where high levels of N are applied. Micronutrient deficiencies in canola ,ue not common, but rnay occur on specific soils. Increases in canola yield with application of B, Zn and Cu have been reported in field studies. Balancd nutrition of canola is important to ensure optimum seed yield and quality as well as the most economic response to applied fetilizer. In field studies, however, Malhi et al. (1988) found that yields of canola were as great withNHi as with NO3, regardless of soil pH or whether the N was broadcast, banded, or treated with a nitrification inhibitor.Although canola is not currently a N-fixing crop, research is being conducted into use of rhizobia on canola. Cocking et al. (1990) reported

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Integration of green manuring as fallow replacement in dryland cereal production requires selection of well‐adapted legumes. The objectives of this study were to (i) analyze vegetative growth of annual legumes and (ii) assess the relative merits of each legume as shortterm green manure crop. Inoculated black lentil (Lens culinaris Medikus), Tangier flatpea (Lathyrus tingitanus L.), chickling vetch (Lathyrus sativus L.), and feedpea (Pisum sativum L.) were tested on an Orthic Brown Chernozem soil (Aridic Haploborolls) at Swift Current, SK, Canada, from 1984 to 1990. Legume species and years differed significantly in dry matter (DM) production of shoots, roots, and nodules; DM partitioning; growth habit; relative growth rate; and weediness. Total legume DM ranged from 601 to 3961 kg ha−1, with 6‐ yr means of 1669 kg ha−1 for black lentil, 1486 for Tangier flatpea, 2230 for chickling vetch, and 3008 for feedpea. Nodulation was most abundant with chickling vetch and least with Tangier flatpea; nodule DM ranged from 2 to 329 kg ha−1. Coefficients of determination between nodule and legume DM were r2 = 0.93*** for chickling vetch and r2 = 0.78*** for feedpea, indicating their ability to benefit from symbiosis with Rhizobium. Nodulation was greatly influenced by soil mineral N and soil water. Average DM allocation to roots as a percentage of total legume biomass averaged =7% for chickling vetch and feedpea and 12% for black lentil and Tangier flatpea. Feedpea canopy height was double to triple that of black lentil. The degree of decumbency (stem length/canopy height) was 1.09 for black lentil, 1.19 for chickling vetch, 1.21 for feedpea, and 1.29 for Tangier flatpea. Growth rate analysis identified chickling vetch as an early‐developing legume. Feedpea and chickling vetch were definitely more suited to green manuring in semiarid climates than black lentil and Tangier flatpea. Feedpea has good growth habits and greatest DM production. Chickling