Potential of Field Pea as a Nutritionally Rich Food Legume Crop

The nitrogen (N) residual effect of field pea (Pisum sativum L.) to a succeeding non-legume crop was determined in a small plot experiment at Scott, Saskatchewan in the moist Dark Brown soil climatic zone, and in a small plot and landscape experiment near Melfort, Saskatchewan in the moist Black soil climatic zone from 1993 to 1995. The N residual effect, defined as the amount of fertilizer N required for a non-legume crop grown on non-legume stubble to produce the same yield as that of the non-legume grown on field pea stubble, averaged 27 and 12 kg N ha−1 at Melfort and Scott, respectively, in the small plot experiment, and 28 kg N ha−1 in the landscape experiment. Landscape slope position and preseeding tillage did not have a significant or consistent effect on the magnitude of the N residual effect of field pea to the succeeding non-legume crop. The N residual effect, calculated using the difference (economic N rate) method, was presumably due solely to the N benefit, with no non-N benefit contribution. The non-N benefit was effectively marginalized when the crop sequence that included field pea was compared with a reference rotation that included a cereal and an oilseed crop. Based on field pea seed yields and the calculated N residual effect, the N credit (N fertilizer replacement value) of field pea to a succeeding non-legume crop in the moist Black soil climatic zone was 15 kg N ha−1 for every 1000 kg of seed. This is slightly higher than the current recommendation of 5 to 10 kg N ha−1 1000 kg−1 seed. Results from the small plot experiment at Scott indicate that current N credit recommendations for field pea are appropriate for the moist Dark Brown soil climatic zone. Key words: Pisum sativum, Triticum aestivum, Hordeum vulgare, Brassica rapa, Linum usitatissimum, nitrogen residual effect

AbstractField pea (Pisum sativum L.), a cool-season legume crop, is known for poor heat tolerance. Our previous work identified PR11-2 and PR11-90 as heat tolerant and susceptible lines in a recombinant inbred population. CDC Amarillo, a Canadian elite pea variety, was considered as another heat tolerant variety based on its similar field performance as PR11-2. This study aimed to characterize the differential transcription. Plants of these three varieties were stressed for 3h at 38°C prior to self-pollination, and RNAs from heat stressed anthers and stipules on the same flowering node were extracted and sequenced via the Illumina NovaSeq platform for the characterization of heat responsive genes. In silico results were further validated by qPCR assay. Differentially expressed genes (DEGs) were identified at log2 fold change, the three varieties shared 588 DEGs which were up-regulated and 220 genes which were down-regulated in anthers when subjected to heat treatment. In stipules, 879 DEGs (463/416 upregulation/downregulation) were consistent among varieties. The above heat-induced genes of the two plant organs were related to several biological processes i.e., response to heat, protein folding and DNA templated transcription. Ten gene ontology (GO) terms were over-represented in the consistently down-regulated DEGs of the two organs, and these terms were mainly related to cell wall macromolecule metabolism, lipid transport, lipid localization, and lipid metabolic processes. GO enrichment analysis on distinct DEGs of individual pea varieties suggested that heat affected biological processes were dynamic, and variety distinct responses provide insight into molecular mechanisms of heat-tolerance response. Several biological processes, e.g., cellular response to DNA damage stimulus in stipule, electron transport chain in anther that were only observed in heat induced PR11-2 and CDC Amarillo, and their relevance to field pea heat tolerance is worth further validation.

The total nitrogen (N) benefit of field pea (Pisum sativum) to a succeeding non-legume crop was measured in a small plot experiment at Scott, Saskatchewan in the moist Dark Brown soil climatic zone, and in a small plot and landscape experiment near Melfort, Saskatchewan in the moist Black soil climatic zone from 1993 to 1995. The total N benefit was calculated as the difference in net N mineralized from soil plus N in the above- and below-ground crop residue between field pea and non-legume stubble-cropped plots over the growing season. Landscape slope position did not affect the total N benefit of field pea to a succeeding wheat crop, and preseeding tillage had an inconsistent effect on the total N benefit between years. The direct N benefit of field pea aboveground residue available to the succeeding crop in the landscape experiment was a minor component of the total N benefit, which averaged 25 kg N ha−1. The total N benefit was equivalent to the N residual effect, defined as the amount of fertilizer N required for a non-legume crop grown on non-legume stubble to achieve the same yield as that of the non-legume crop on field pea stubble. This confirms that the N residual effect of field pea to the succeeding non-legume crop was due to the N contribution; any non-N contribution to the N residual effect was effectively excluded. Key words: Pisum sativum, Triticum aestivum, Hordeum vulgare, Brassica rapa, Linum usitatissimum, total nitrogen benefit

Analysis of the height and leafiness of plants of oats (fodder), pea (spring), field pea was carried out depending on the seeding rates and fertilization. It was established that under the increase in the seeding rate of oats by 25 %, the height of plants of the grass and legume components rose irrespectively of the rate of fertilization. The leafiness of leguminous crops was 2.9—3.1 times higher than that of oats.