Evaluating potential forages for suppressing foxtail barley and downy brome in saline pastures and hay fields

Non-Peer Reviewe

Evaluating potential forages for suppressing foxtail barley and downy brome in saline pastures and hay fields

Non-Peer Reviewe

Does seed size affect alfalfa establishment and productivity in saline seedbeds?

Non-Peer ReviewedLarge, medium and small seeds of Rangelander alfalfa, were sown in saline media in Canada’s Salt Tolerance Testing Lab. The emergence and survival data indicate that large-size seeds confer a degree of salinity tolerance to their emerging and developing seedlings. The large seeds emerged in numbers 10 and 23 % greater than the plants from medium and small seeds grown in 18 and 24 dS m-1 solutions, respectively. The seed-size advantage, evident in plant heights just 14 days after seeding, persisted into forage harvests which also showed increased biomass yields at all salinity levels at the first harvest cut. Although the seed-size yield advantages diminished with successive harvests, higher yields persisted at the 12 and 18 dS m-1 salinity treatments for the crops planted with large seeds

Pre-irrigation of a severely-saline soil with in-situ water to establish dryland forages

Non-Peer ReviewedAlfalfa serves as one of the most important forage plants in North America. It is also the recommended remedial crop for dryland salinity control. But, because of its limited salt tolerance, it does not establish satisfactorily in severely or moderately saline soils. A series of irrigations with the in-situ ground water located beneath a severely-saline site were delivered across seedbeds prepared within the same site prior to seeding ‘Beaver’ alfalfa (Medicago sativa) and ‘ AC Saltlander’ green wheatgrass (Elymus Hoffmannii). In this field study conducted in semiarid Saskatchewan, fall irrigations with 4.6 dS/m-water from a shallow, on-site, backhoe-dug well fitted with a solar-powered pump preceded spring seeding. Irrigation treatments ranged from zero to 2530 mm in total applied water. Plant emergence, spacing, height, cover, and forage yield of the alfalfa were significantly improved following pre-irrigation. Mean plant emergence increased from 20 to 79% for the alfalfa. The wheatgrass height and forage yield also improved significantly, but showed only an upward trend in emergence, spacing, height, and cover. The mean plant height in July increased from 90 to 159 mm for the wheatgrass and from 35 to 140 mm for the alfalfa. Based on linear regression of irrigated volume, every 119.3 mm of irrigated, in-situ water up to 2530 mm increased alfalfa forage yield by 10 g/m2

Does it pay to fertilize a mature forage stand on a severely saline field?

Non-Peer Reviewe

Is it economical to fertilize a mature forage stand on a severely saline site? Preliminary results

Non-Peer Reviewe

Agriculture and agri-food Canada’s salinity tolerance testing laboratory

Non-Peer Reviewe

Salinity tolerance screening for biodiesel cultivars

Non-Peer Reviewe

Measuring salinity

Non-Peer ReviewedRoot-zone salinity reduces crop yields. The extent of the reduction depends on the kinds and concentrations of salts existing in the soil solutions across the field. The salts which cause root-zone salinity typically dissociate into sodium, calcium, magnesium, and sometimes potassium cations together with chloride, sulphate, bicarbonate, and carbonate anions. These ions, when dissolved in soil water and concentrated in excess of plant needs, can disrupt crop water uptake and plant metabolism. We easily recognize the existence of salinity when we see white salt crusts on soil surfaces. But, root-zone salinity may also exist in field locations which never show white crusting. Surveying and mapping a field using geo-physical instruments operating on the soil surface can reveal this hidden root-zone salinity. Although measurements with these instruments are affected by soil texture, chemistry, water-content, temperature, and other factors, basic indices can still be calculated by linking survey measurements with detailed salinity values derived from soil cores extracted as part of the survey

Using flow gauges to determine stem and root conductance in hybrid poplars.

Non-Peer ReviewedA study was conducted using sap flow gauges to determine stem and root conductance in hybrid poplars at two sites near Swift Current, Saskatchewan. At the Rushlake site, sap flow rates were compared between CanAm and Walker poplars using Dynamax (Model SGA-10) stem flow gauges. The primary objective was to determine if the difference in susceptibility to midsummer terminal shoot dieback in Walker and CanAm poplar clones could be attributed to leaf-specific conductance. Walker poplars appear to be well-suited to mesic sites and, under good soil moisture conditions, perform better than CanAm . However, they are susceptible to mid-season terminal shoot dieback, while CanAm poplars do not seem to be as susceptible. We suspect that this is primarily attributable to a greater leaf-specific conductance (LSC) of CanAm poplars. As a tertiary cause, perhaps CanAm poplars achieve a more complete stomatal closure during periods of extended vapor pressure deficits. The gauges were mounted at the distal ends (where the shoot diameter is about 10 mm) of actively growing branches near the crown of each tree. For a period of 14 days, the sap flow rates of each tree were measured. Preliminary results indicate that CanAms did indeed have a greater LSC and showed higher stem flow rates than Walker poplars. Under the study conditions at the Rushlake site, air temperatures were not of sufficient magnitude to determine differences in leaf stomatal closure between the CanAm and Walker trees. The LSC characteristics, however, would have benefited the CanAm poplars in functioning under extended vapor pressure deficits. A secondary objective was to determine if differences in root conductances of poplars subjected to varying saline conditions were possible to measure using sap flow gauges. Although great care must be taken during gauge installation on tree roots, we found it is possible to measure root sap conductance on trees subjected to varying levels of salinity