Here are my notes from the 2011 Manitoba Soil Science Society Meeting. Due to bad weather and closed highways, I missed the second day of the meeting.
H. Asgedom’s talk on Nitrogen Oxide Emissions from Urea and Dairy Manure compared nitrous oxide emissions from five treatments: control unamended, ESN, Solid Dairy manure, Urea, SuperUrea. Urea and SuperUrea showed higher cumulative nitrous oxide, ESN plots had least cumulative nitrous oxide. For manure, nitrous oxide release was triggered by fall manure application. Yield seemed to correspond to cumulative emissions – higher nitrous oxide = higher yield.
Krista Hanis discussed Eco-system Scale Methane Flux. Her research was up north near Churchill. 2009 spring results show a gradual increase in methane, not a burst. 2010 fall results show no big burst during freeze-up either. Their current hypothesis is that a high water table decreases methane losses through consumption or trapping methane in bubbles. The greatest losses were when the water table was 10cm below surface and air temperatures were warm.
Mario Tenuta asked Is it possible to create profitable Green House Gas (GHG) Neutral Agroecosystems? Why pursue Green House Gas (GHG) Neutral Agroecosystems? Three possible answers are: Carbon trading, improving system efficiency and profitability, and being good neighbors and limiting atmospheric GHG. The current Agricultural problems with GHG are problems of design: crops are poor competitors, most are annuals (not active in winter), most crops don’t fix N, N in residues is subject to losses, farmers tend to maximize useful yield/land area. Crops will be dependent on N inputs for some time. Alfalfa brings down net GHG, as do most other perennials.
Ikechukwu Agomoh discussed research into Coagulant/Floculant effects on swine manure separation. The conclusion was that most of the solids settle out by 8 hours regardless of additive (including control).
Ray Bittner talked about his experience with Phosphorous Ramp Calibration strips in the Interlake. In the Interlake all crops are dependent on supplemental P. Extra P promoted alfalfa growth (vs. grass). With low P soils (4-5 ppm) there was definite yield response, soil with 15 ppm or higher of P showed no yield response, and soils with around 10 ppm had some yield response. P removal in feed was higher in high P soils.
General trend is increased soil test P with increased application. They got two different results: Hilbre site – never worth applying extra P; Arborg site – always worth applying P.
Waraidzo Chiyoka studied Nitrogen Uptake by Barley amended with anaerobically digested manure. Objective: Determine uptake in anaerobically digested manure versus raw manure. Pelletization reduces moisture wchich increases haul distance. Nitrogen uptake increased for everything except pellets. N availability did not differ between raw manure and separated solids. Yield increased with increased N regardless of the form of N.
D. Ige’s talk on Use of wheat dried distillers grain with and without enzyme supplement in pig diet: effect on phosphorus solubility in manure amended soil had interesting results. P in DDGS has been shown to be more available to animals than that in grains. Five diets were formulated.
Feces and urine collected and applied to different MB soils. DDGS had no effect on P solubility in coarse soils, influenced P solubility in fine soils,
Caution must be exercised in assessing effects of diets as effects can vary with soil.
Xiaopeng Gao talked about Producing Crops with Low Cadmium and High Zinc on the Canadian Prairies. There are health concerns with excess Cd or insufficient Zn. He studied the effects of common ag practices on Cd and Zn levels. Cultivar and soil type has effect on CD and Zn (lower Cd, higher Zn in Clay vs FSL). More Cd in fertilizer = more Cd in crops. N fertilizer increased grain Cd at all site-years. N fertilizerdecreased grain Zn at all site-years. Selection of suitable source, timing, and placement of N is important. Effect of preceding crop depends on crop species. Grain Zn was higher after flax than after canola, grain Cd not affected. Either long term or immediate P fert increased grain Cd , decreased grain Zn. Tillage had little effect on either ZN or Cd.
I love listening to Rigas Karamanos’ talks – he always has interesting stuff to report. Updated Phosphorus Recommendations for Wheat, Barley and Canola in Manitoba. Hi goal here is attaching economic analysis to agronomic response. All crops have a point where yield response is unlikely. The current figures for P removal are: Barley P removal = .4 lb/bu, Canola 0.9, CWRS =0.55. Rigas has written a paper showing probability of response to P fert based on soil test:
Soil Test P : Probability of Response
<5 ppm : 100%
6-10 : 71%
11-15 : 50%
16-20 : 50%
21+ : 16%?
Net return = (crop price x yield increase) – (nutrient price x nutrient rate). Rigas has a P rate of return calculator available.
Karimi Dehkordi spoke on Measuring the magnitude and variability of nitrate leaching using field core lysimeters. N leaching into drinking water is health concern. Objective is to determine influence of liquid manure, solid manure, and conventional fertilizer on N leaching. A Lysimeter is essentially big pipe put vertically into the ground. Two plant samples were collected: early and at harvest. Leachate was collected at 5 intervals
Leaching of N is much greater on annual crops than on perennials. Water leaching in perennials was also less than in annuals. Perennials had greater biomass.
S. M. Sayem discussed their research on In-situ measurement of nitrogen mineralization from manures using anion exchange resin. The problem is that we need better measurements of nitrogen release from manures. The study took place at Glenlea and Carman and used resin and soil analyses. Ammonium N declined with time andapproached background levels after two weeks. Nitrate N increased with time due to nitrification and mineralization.
Total Mineral N was 4 times greater at Carman than at Glenlea. Anion resin worked at Carman but not at Glenlea – it appears that it works in light soils but not clays.
Daniel Rheault gave some preliminary results for Quantifying the Relationship between Soil P Measures and P Loss by Runoff for Manitoba Soils under Field Conditions: Year 1 Preliminary Results. The study used four sites plus one baseline (Rosser). The general trend is that higher soil P means higher runoff P. They used Total Disolved P (TDP) rather than just Total P as it gave a slightly better relation to runoff P. All three agronomic methods (olsen, kelowna, melich) of measuring soil P were pretty close. Environmental methods were similar. 0-5cm gave better relationship than 0-15cm (but they are highly correlated). They didn’t see evidence of a point at which runoff P increased greatly. Increased residue meant decreased runoff at 3 of 4 sites (with the exception being a no-till site). As time goes on runoff reduces. Site is a huge factor for P runoff (soil texture, topography).
M.D. Timmerman decided to go for the long title challenge with Managing fourteen hundred-pound bundles of fertilizer bound with twine – MAFRI investigates bale grazing and other extensive fall/winter feeding practices. Early extension in this area dealt with swath grazing. Why not keep the cattle in the yard? Potential cost reductions, potential contamination risk reduction, soil fertility, soil quality, agronomic driver is better crop growth, better plant diversity. Bale grazing gives lots of soil test variability (concentric rings). Are the nutrients beter managed in the field or in the yard? Mitchell was able to give a definite it depends. I didn’t get to ask a question but the one that pops to mind here is how do the overwintering cattle losses from bale grazing compare to standard overwintering losses?
I.D. Amarakoon studied Chlortetracycline, sulfamethazine and tylosin losses in surface runoff following field application of beef cattle manure. Antibiotics are powerful tools to treat and prevent disease in livestock. 75% of livestock antimicrobials are excreted, which may lead to increases in antibiotic-resistant diseases. In this study manure from cattle given three different antibiotic treatments was broadcast or incorporated. Broadcast versus incorporation had different effects for different antibiotics – i.e. broadcast was not always worse than incorporation or vice versa.
Lindsey Andronak looked at Urban Atmospheric Deposition of Selected Pesticides. This study looked at bulk atmospheric deposition – rainfall and particulate matter from non-point sources. Tests were done for 72 chemicals from May to Sept. There was also work done on correlating amount of rainfall to deposition amounts. In their two sites in south Winnipeg, 19 pesticides were detected. The rainfall/pesticide correlation was decent R^2 of 0.5824. Particulate matter deposition remained a factor – on one of the few rain-free weeks they still had chemical residue deposited. Atmospheric deposition is a mjor source of non-point contamination. There were both rural and urban sources for the chemicals.
Xuelian Bai gave us a rundown of Sorption and Degradation of 17B-Estradiol-17Sulfate in Agricultural Soils. E2 is a natural compound from women, dairy cattle, sows. Half life in lab is 1/2hour to a few days, in the wild seems to last longer. Organic carbon content is a big contributor in the dissipation of E2
P. Messing presented A Regional Study on the Pesticide Concentrations in Air. As opposed to Lindsey Andronak’s study, this one looked at chemcal traces in the air, not deposition. They used Passive Polyurethane Foam samplers (very low flow) at seven sites in manitoba (mostly in the south). In their northern sites, they mostly found traces of de-registered chemicals. In the east (experimental lakes) no pesticides were found. Spatial variablity of active ingredients is evident across the province and there are also small-scale variations. Current pesticides seem to breakdown more quickly than older ones.
Adam Guy gave us a study of the Impacts of major flooding on an urban environment. The flloding in Fargo had many factors: heavy Autumn precipitation, heavy winter snowfall, unfavorable melting pattern, heavy rain on melting snow, maybe urbanization, maybe land management (better drainage). What is the effect of flooding on water quality? What is the effect of flooding on sediment contamination? They did analysis of new sediment and existing soil and concluded that sediment was generally richer in nutrients and carbon than existing soil.
Alison Murat showed the results of an early study of Germination and Early Survival of Brassica Species in Organic and Mineral Soils Contaminated with Multiple Trace Elements. The site they were looking at had contamination due to idustrial activity and conventional remediation. Objective: evaluate three species to germinate and survive in contaminated soils and adjust conditions to improve plant growth. In general organic soil was more contaminated than mineral soil. Contaminated soil negatively impacted growth of Brassica – i.e. all the plants died. Future work will need to improve plant growth and survival – add nutrients, different species. Their next try will be with tufted hairgrass. Future work – looking at multiple growth cycles and experimental factors (soil type, fertilizer tpe, EDTA rate)
Yi Zhang spoke on Soil survey data for managing soil salinity. Manitoba has 0.6 million saline acres, Sasktachewant has 3.3 million, and Alberta has 1.6 million acres. Soil surveys evalute salinity in several ways: site observation, soil sampling, lab test, field instrument survey. Electromagnetic induction is used to map salinity, but it has to be coupled with lab tests. They use DUALEM with GPS and GIS to map salinity. Salinity survey is often used with precision farming. Electrical conductivity maps to soil textures as well as salinity. Salinity levels correspons inversely with crop yield in many cases (there are other factors too). In extreme cases, salinity affects Ag Capability class.