On-farm Evaluation of the Agronomic & Economic Benefits of Organic Based Crop Nutrient Sources

Collaborators: Mark & Tracy Vetsch (Valleyview), MD of Greenview

Funders: Prairie Organic Grain Initiative, Organic Alberta

Research Coordinator: Dr. Akim Omokanye

Foliar feeding involves the application of nutrients (through spraying) to plant leaves and stems, and their absorption at those sites. It is a viable means of enhancing crop nutrition. Foliar feeding has been used as a means of providing supplemental doses of minor and major nutrients, stimulants, and other beneficial substances. Observed effects of foliar feeding have included yield increases, resistance to diseases and insect pests, improved drought tolerance, and enhanced crop quality. Plant response is dependent on species, nutrient form, concentration, and frequency of application, as well as the stage of plant growth. Foliar applications are often timed to coincide with specific vegetative or fruiting stages of growth. Several foliar feeding nutrients are available in the market, but in this study, we only used Compost Tea, Fish Fertilizer and Liquid Carbon 9-5-3, to learn if there was a measurable benefit to foliar feeding using these products.

Objectives

To find ways to improve plant and soil health, and ultimately yield and profitability.

Methods

The study was carried out at Mark and Tracy Vetsch’s farm in Valleyview, MD of Greenview, Alberta. It was an on-farm study using multiple acre test plots across the entire field.

Two crop types (oats and peas) were used on separate fields, which were far apart. The oats were seeded on the field at NW5-72- 21W5 and the peas were seeded on the field at NW7-72- 21W5. Both fields were cultivated before seeding. Soil samples were taken from 0-6” depth just before the foliar feeders were sprayed.

Table 1 shows soil nutrients and quality as well as soil health indicators for both fields. The soil tests showed a pH of 5.9-6.1 for the fields. Soil organic matter was higher for the oat field (4.7-8.7%) than the pea field (2.8-3.0%). The soil nitrate-N was lower for the pea soil (4-5 ppm, 8-10 lbs/acre) than the oat soil (15-36 ppm, 30-72 lbs/acre). The soil health index was lower for the pea field (27.5) than the oat field (32.0), indicating that the oat field was probably slightly healthier and had slightly more microbial activities than the pea soil.

Table 2 shows % base saturation obtained from the fields and the desired levels for each measurement. Except for %Mg, which was within the 10-20% ideal (optimum) level for crop production, other elements (K & Ca) as well as K/Mg ratios were all below the ideal levels for crop production.

Morgan oats was seeded @ 140 lbs/acre (42 lbs/bushel) into 2.0” depth on May 27.

Meadow peas (yellow) was seeded @ 240 lbs/acre (12 seeds/ft2 ) into 1.5-2.0” depth. The pea seed was inoculated with Tag Team® + AGTIV®.

On June 7, red clover was seeded into the peas @ 5lbs/acre with a double disc drill (DDD). Peas were beginning to emerge when the red clover was being seeded. On June 10, sweet clover was seeded into the oats @ 6lbs/acre with a DDD when the oats were about 2” tall.

The organic based foliar feeders (fertilizers) used were Compost Tea (CT), Fish Fertilizer (FF) and Liquid Carbon 9-5-3 (from Canada Humalite International (CHI), Edmonton). The foliar fertilizers consisted of a combination of CT+FF as one foliar feeder type and Liquid Carbon 9-5-3 (Humalite) as another type of foliar feeder.

The treatments from the foliar feeders tested were:

1. Control

2. Humalite (CHI liquid carbon 9-5-3)- Just one application on July 5 @ 4 L/acre with 18 L of water

3. Early spraying of Compost Tea/Fish Fertilizer (CT-FF Early)– The combination of compost tea and fish fertilizer was sprayed early on July 6. This was done just once.

4. Delay spraying of Compost Tea/Fish Fertilizer (CT-FF Delay)– The combination of compost tea and fish fertilizer was sprayed early on July 20. This was done just once as well.

5. Two applications of Compost Tea/Fish Fertilizer (CT-FF 2Apps)- The combination of compost tea and fish fertilizer was sprayed twice, first on July 6 and then July 20.

Compost tea was applied @4 L/acre and fish fertilizer @ 6 L/acre. Water was 50 L/acre.

The budget for CHI liquid carbon 9-5-3 and compost tea + fish fertilizer were:

• Cost of compost tea (CT) + fish fertilizer (FF) = $35.00/acre ($10 for CT product, $15 for FF product & $10 for spraying application)

• Humalite (CHI liquid carbon 9-5-3) = $18.80 /acre (for product & spraying application).

Measurements taken:

• Soil nutrients and soil health indicators– base data sampling was taken this year in spring. Another set of samples will be taken in spring 2018 to enable comparisons of soils taken in both years.

• Crop yield and quality, thousand kernel weight, test weight (only for oats) were determined.

• The peas were assessed for nodulation.

• Straw yield and quality were determined as well

• A spectrometer equipment known as a Green-Seeker was used to measure Normalized Difference Vegetation Index (NDVI) at early/mid pod development stage.

• Simple economic performance using direct input consts and revenues.

Results & Discussion

Pea Trial

Crop Yield (Table 3)

The pea yield varied from 35.1 bus/acre for C+FF Delay to 45.7 bus/acre for CT+FF 2Apps. For some reason that is difficult to explain, CT+FF Delay produced lower yield than Control. For other foliar feeding treatments, yield over Control was 3% for CT+FF 2Apps, 45 for Humalite and 12% for CT+FF Early. Overall, in this study, foliar feeding treatments did not seem to improve yield over Control treatment much.

1000-seed weight (Table 3)

The thousand pea grain weight varied from 209 grams/1000 grain for CT+FF Delay to 218 gramms/1000 grain for Humalite. Also, CT+FF Delay had lower 1000-seed weight than Control ans the reason for this iss difficult to explain as well.

NDVI Values (Table 3)

The results of the Green-Seeker optical unit showed that the NDVI score was highest for CT+FF 2Apps. Generally, all foliar feeding treatments seemed to give higher NDVI values than Control, which had an NDVI score of 0.78.

In simple terms, NDVI is a measurement of plant health based on how a plant reflects light (usually sunlight) at specific frequencies. The rules of thumb say that an NDVI plant health rating between 0 and 0.33 indicates unhealthy or stressed plant material, 0.33 to 0.66 is moderately healthy, and 0.66 to 1.00 is very healthy. Therefore looking at NDVI values, all pea stands in this study seemed to be healthy. CT+FF 2 Apps appeared to produce slightly healthier pea crop than other foliar feeding treatments tested as well as Control. Except for CT+FF Delay, all foliar feeding treatments had higher NDVI scores than Control.

Grain Quality (Table 3)

The pea seed crude protein (CP) appeared to be similar for all foliar feeding treatments tested here, though CT+FF Delay foliar treatment tended to be slightly higher. There wasn't any apparent improvement with foliar feeding treatments here over Control for both macro and trace minerals measured.

Pea Straw Quality (Table 3):

The straw CP was generally below 5%, varying from 3.37-4.82%. A mature beef cow requires a ration with CP of 7% in mid pregnancy, 9% in late pregnancy and 11% after calving. Looking at the straw CP obtained in this study, it is obvious that all foliar feeding treatments and Control had very low CP and they thereby all fell far short of meeting the CP requirements of mature beef cattle.

The straw energy (%TDN) varied from 50.2 to 52.7% TDN for foliar feeding treatments and Control. For a mature beef cow to maintain her body condition score (BCS) through the winter, the ration must have a TDN energy reading of 55% in mid pregnancy, 60% in late pregnancy, and 65% after calving. Overall, all foliar feeders and Control fell short of meeting the TDN requirements of mature beef cattle at different stages.

The NEm varied from 1.17 to 1.24 Mcal/kkg for the foliar feeding treatments and Control. The NEm requirements for mature beef cattle (1.19-1.28 Mcal/kg0 have been met by all treatments. The NEm is an estimate of the energy value of a feed used to keep an animal in energy equilibrium, neither gaining weight nor losing weight.

Generally, the foliar feeding treatments did not consistently improve straw minerals more than Control. However, the pea straw Ca, K & Mg contents appeared to be better with CF+FF Early application than other foliar feeding treatments.

In terms of beef cattle mineral requirements, onnly the Ca, K & Mg requirements of mature beef cattle were met by all foliar feeding treatments and Control. Other minerals from all treatments fell short of meeting mature beef cattle requirements.

Oats Trial

Grain Yield

In this study, the oat grain yield did not seem to be improved by foliar feeding treatments over Control. Overall, the oat grain yield varied from 76.1-83.6 bus/acre.

1000-Kernel Weight and Test Weight

The 1000-kernel weight and oat test weight appeared to be similar for all treatments. The 1000-kernel weight varied from about 42 to 46 grams/1000 oat kernels, while the test weight varied from 36-39 lbs/bus.

NDVI Values:

The results of the Green-Seeker optical unit showed that NDVI score was similar and higher for all foliar feeding treatments than Control. Following the rules of thumb, which say that an NDVI score between 0.66 to 1.00 indicates that the plant is very healthy, all foliar feeding treatments as well as Control had healthy plants. However, the NDVI scores of 0.81-0.85 for the foliar feeders could indicate the positive effects of the foliar feeders in producing even healthier plants than Control (NDVI=0.77).

Oat Straw Quality (Table 5): The oat straw CP content from all foliar feeding treatments as well as control was generally below 4% CP. The oat straws from all treatments therefore fell short in meeting the minimum CP requirement of mature beef cattle, which is 7% CP for a dry gestating beef cow in mid pregnancy. Similarly, the minimum energy requirement of mature beef cattle, which is 55% TDN at mid pregnancy was not met by any foliar feeding treatments and control, as the oat straw TDN was generally <50% TDN. Except for K & Na, the minerals fell short of meeting mature beef cattle mineral requirements.

Because of the inability of oat straw to meet the required CP, TDN and minerals for mature beef cattle, some form of supplementation would be required when oat straw is fed to mature beef cattle.

Cost of Production Comparison for Peas and Oats

The cost comparison of foliar feeding peas and oats compared to Control is provided above in Table 5. As expected, total direct (input) cost was lower for Control than foliar feeding treatments using CT+FF and Humalite for both peas and oats. The highest input costs obtained for CF+FF 2 Apps in both cases, simply resulted from the second application of CT+FF.

For peas, the return was highest for CT+FF Early ($485.50) and lowest for CF+FF Delay ($326.50).

Only 2 (Humalite and CT+FF Early) of the 4 foliar feeding treatments appeared to have some positive gains over control. The extra income from the 2 treatments over the control was $8.70/acre for Humalite and $43.50 for CT+FF Early.

For oats, the return was lowest for CF+FF 2Apps ($287.60) and highest for Control ($383.60). The profit over control for oats was negative for the 4 foliar feeding treatments tested here.

Conclusion

The results did not show much improvement in crop yield and quality from the foliar feeders (fertilizers) tested compared to control. However, from the NDVI scores obtained in this study, there seemed to be an indication that there were some positive impacts on crop health from 3 (Humalite, CT+FF Early and CT+FF 2Apps) of the 4 foliar feeding treatments. For peas, there seemed to be some extra income from Humalite and CT+FF Early over control. Overall, there was not a clearly defined outcome. Timing of applications of the foliar feeding treatments used in this study was thought to be partially responsible for lack of any significant responses this year. The Compost + Fish fertilizer treatments in particular were applied earlier than recommended. The producer would like to replicate the trial a second year to be more certain of outcomes.