Collaborating Producer: Paul & Lori Kinnee, Brownvale
Research Coordinator: Dr. Akim Omokanye
Many producers want to increase their management to better utilize their pastures for livestock production. Under the right condition, fertilizer application can be one of the most cost-effective methods to improve forage yield and quality. In addition to solid fertilizer application, foliar fertilizer can also be used to rejuvenate pastures. Foliar fertilization can correct deficiencies, strengthen weak or damaged crops, speed growth and grow better plants. Foliar nutrients are mobilized directly into plant leaves, which is the goal of fertilization to begin with, increasing the rate of photosynthesis in the leaves, and by doing so stimulating nutrient absorption by plant roots. PCBFA was approached by the collaborating producer to carry out studies on the use of foliar fertilizer to rejuvenate pasture and particularly to examine the effects the foliar fertilizer will have on grasshoppers and pasture production. With the product (Best Foliar Fertilizer), the producer understands that grasshopper populations should be reduced because of its ability to increase forage brix (sugar) level. Grasshoppers do not have a pancreas so they cannot process/digest sugar and therefore would tend to go after unhealthy plants more than they would healthy ones, with a higher brix content. Brix is the measure of the sugar content of a plant and is measured by a device called a refractometer. The objectives of this study are to examine the effects of foliar fertilizer on soil nutrients, forage brix level, forage yield and feed value.
Methods
Site: The project is located in Brownvale (MD of Peace) on RGE road 263 and on 225 acres of land.
History of Site: The site was used as a hay field for years, but used as pasture for the last 3 years. Dominant forages are fescue, timothy and quack grass, and some alfalfa and a few stands of clover.
History of Site: The site was used as a hay field for years, but used as pasture for the last 3 years. Dominant forages are fescue, timothy and quack grass, and some alfalfa and a few stands of clover.
Experimental Procedure: The south side section (about 75 acres) of the entire field was used for data collection. We had 2 strips, where 1 was a test/control strip and 1 which had foliar fertilizer spray. Best Foliar Fertilizer (Granular Foliar Application) was used for the project.
Foliar Fertilizer Application: One 22.5 kg pail treats 32 acres. Though the foliar fertilizer should be applied 2 or 3 times during the growing season, in this case we were only able to spray once. Spraying was done on June 6, 2012 using a 10 -gallon nozzle. The foliar fertilizer is a custom blend of nutrients, such as organic or inorganic fertilizers, that promote plant growth from seedling to maturity. It contains 7% N, 35% P, 8% K, 2% Mg and 6% S. For soil rejuvenation, it contains 0.1% N, 0.02% P, 0.14% K, 0.007% S and 0.013% Ca. The product is used to restore soil nutrients, microbial populations and to promote plant growth. For more information, please visit: http://www.bestenvirotech.com/best-farmingsystem.
Measurements: On July 13 (5 weeks after spraying) and August 24 (11 weeks after spraying), forage yield and brix readings were taken from both test and sprayed strips. Forage samples were analyzed for feed value. For the brix readings, different plant types present at sampling were identified, grouped as grasses, legumes and others, and the respective sugar (brix) levels determined. On August 24, soil samples were also taken to a depth of 6 inches and submitted to EXOVA in Grande Prairie for analysis.
Grasshopper Population: The site is known for heavy grasshopper infestation. But in 2012, there was no grasshopper infestation in the area, so we couldn’t ascertain any effects the foliar fertilizer spray would have had on grasshopper population/control. Next year (2013), efforts will be made to assess any effects on grasshopper population (if any infestations).
Results and Discussion
Soil Nutrient and Quality Indicators: Soil pH seemed to be improved by the foliar fertilizer application by 0.4 units over the unsprayed test strips (Table 1). This is a significant increase in soil pH, based on the fact that the foliar fertilizer was sprayed just once in the season. It is also significant based on the amount of liming, energy and time that would be saved if the soil pH was to be increased by such unit. Soil pH basedata was 6.0, an indication that spraying of the foliar fertilizer improved soil pH by 0.3 units probably because of the presence of 0.013% Ca in the soil rejuvenation constituent of the foliar fertilizer.
Compared to the unsprayed test strip, soil N, P, K and S all appeared to be improved by the application of foliar fertilizer (Table 1). The effects were more for soil P, K and S. Overall, spraying increased soil N, P, K and S respectively by 182%, 227%, 270% and 325% over the test strips. Base saturation (BS) is the percentage of total cation exchange capacity occupied by base cations such as Ca, Mg, Na and K. Looking at the BS values, spraying increased BS by 121% over the unsprayed test strip (Table 2). With the exception of Na, which was similar for both sprayed and unsprayed strips, spraying appeared to have generally increased the base cations (Ca, Mg & K) (Table 2).
Forage DM Yield and Moisture Content: Forage DM yield on July 13 (5 weeks after spraying) was 6608 lb/ac for the sprayed strip and 4027 lb/ac for the unsprayed test strip, giving a difference of 2581 lb/ac between the two treatments (Figure 1). But on August 24 (11 weeks after spraying), the difference between both sprayed and unsprayed test strips was only 354 lb/ac, in favour of the sprayed strip. Moisture content at harvest was lower for the unsprayed test strips than the sprayed strip in July and August respectively, by 2.7 and 5.8% (Figure 2).
Forage Feed Value: Compared to the unsprayed test strip, forage crude protein (CP) as well as P, Mg and K contents were all improved by foliar fertilizer application both at the July and August sampling dates (Table 3). The most significant effect was on protein content, which was 177% and 155% higher for sprayed over the unsprayed test strips respectively, for samples taken in July and August. Forage Ca content was particularly higher in July than August sampling date. In July, the sprayed strip significantly improved forage Ca content over the unsprayed strip but this was not consistent throughout the season as shown by the Ca content values for both sprayed and unsprayed strips in August (Table 3). Similarly, detergent fiber contents (ADF & NDF), energy content (TDN), digestible energy (DE) and the relative feed value (RFV) were all significantly better with the sprayed strip than the unsprayed test strip, both at the July and August sampling dates.
For cows in the mid-pregnancy stage, which require 7% CP, only the unsprayed test strip forage sampled in August failed to meet this requirement. The CP of sprayed strip forage sampled in July met and far exceeded the 11% CP required by cows after calving.
Forage Brix (sugar) Level: Table 4 shows the mean Brix readings following foliar fertilizer spraying treatments. With the exception of other plants, spraying significantly increased brix sugar levels over the initial basedata readings taken before spraying was done. After spraying, alfalfa significantly had higher brix (14.20%), followed by grasses (11.30%) and then other plants (including dandelions, 6.86%). Reports from producers in the U.S. have shown that with high sugar, grasshoppers would normally die or leave as fast as their little hoppers can take them. Brix was higher for the sprayed strip than the unsprayed test strip, particularly in August.
Brix Readings and What They Tell Us (http://www.ag-usa.net/brix_test_meaning.htm) The Brix is equal to the percent crude carbohydrate per 100 pounds of juice. The higher the carbohydrate in the plant juice the higher the mineral content of the plant, the oil content of the plant, and the protein quality of the plant. For example, if you were to have 100 pounds of alfalfa that has a Brix reading of 15 it would mean that there would be 15 pounds of crude carbohydrates if the alfalfa was juiced and dried to 0 percent moisture. By dividing 15 by 2 it tells us that the actual amount of simple sugar would be equal to 7.5 pounds.
Crops with a higher refractive index will have a higher sugar content, higher protein content, higher mineral content and a greater specific gravity or density. This adds up to a sweeter tasting, more mineral nutritious feed with lower nitrates and water content and better storage attributes. Crops with a higher Brix will produce more alcohol from fermented sugars and be more resistant to insects, thus resulting in decreased insecticide usage. For insect resistance, maintain a Brix of 12 or higher in the juice of the leaves of most plants. Crops with a higher solids content will have a lower freezing point and therefore be less prone to frost damage. Brix readings can also indicate soil fertility needs. If soil nutrients are in the best balance and are made available (by microbes) upon demand by plants, readings will be higher.
When the phosphate levels in the soil are not up to what they should be, the sugar in the plants will vary from the bottom of the plant to the top. In other words, the Brix reading at the bottom of the plant will be higher than the top of the plant. The better the phosphate levels in ratio to potassium, the more even the Brix reading will be all over the plant. Also the better the phosphate levels in ratio to potassium the less fluctuation there will be in the Brix reading in any given 24 hour period.
You will also note that when you are looking into a refractometer, you will sometimes be able to see a very sharp line which is very easy to read, while at other times it may be a very hazy line and not well demarcated and so difficult to read. The very sharp and dark and easy to read line means the crop is lower in calcium and higher in acid. A very diffuse and hard to read line tells one that the calcium is higher and the acid is lower in the plant. This is why a lower Brix reading on a plant will actually taste sweeter when there is high calcium than one that may have a little higher Brix reading and a low calcium. The available soluble sugar is what gives taste and sweetness to food. The more calcium in the crop along with the sugar, the sweeter the taste even though the Brix reading will be the same on two samples.
Future Plans: The trial will continue in 2013 with 2-3 spraying times. Please stay tuned for more information.