-New American Organics-
Save on every order! BECOME A PREFERRED CUSTOMER 1-800-717-1308
The dramatic increase in sustainable agricultural methods and associated use of natural fertilizers has increased performance and yield inquiries from growers. Still, many homeowners and commercial growers use water-soluble, salt-based inorganic products.
This study compared the performance of AGGRAND natural fertilizers with the performance of a leading inorganic fertilizer when applied to garden vegetables in raised planting beds. Each bed included four garden vegetables: sweet corn, potatoes, tomatoes and bush green beans. Parameters evaluated include total weight for each vegetable and plot, average vegetable weight per plot, maximum vegetable length or diameter and total number of vegetables per plot.
Plots fertilized with AGGRAND natural fertilizers outperformed the plots fertilized with the leading inorganic fertilizer and the control plots where no fertilizer, only water, was applied.
The practice of sustainable agriculture, or what is commonly known as organic farming and animal husbandry, evolved from work performed by researchers Dr. William Albrecht of the University of Missouri, Rudolf Steiner in Germany and Sir Albert Howard in England during the first half of the 20th century. The term “organic” as it relates to agriculture was originated during the same period in England by Lord Northbourne, agriculturalist, as an abbreviated description of farming by recognizing a concept known as “dynamic-living-organic-whole.” This statement expresses the concept of using natural fertilizers and soil amendments to maintain and enhance soil fertility while rejecting the use of synthetic chemical fertilizers and pesticides; all while being supported by livestock production (Thilmany, 2006). The implementation of these concepts assisted in the establishment of the Soil and Health Foundation by publisher J.I. Rodale in 1947, eventually known as the Rodale Institute. The Rodale Institute is a leading advocate for organic and sustainable agriculture and operates a 333-acre “organic” farm near Kutztown, Pa. (The Rodale Institute, 2010)
In recent years, The Rodale Institute’s vision has caught the interest of the American consumer and farmer alike. In 1990, sales of organically grown food and beverages totaled $1 billion and increased to $20 billion in 2007, with an anticipated annual growth rate of 18 percent from 2008 to 2010 (Organic Trade Institute, 2010). However, organic, natural, or sustainable agricultural growing systems do not necessarily yield “certified organic” crops or produce.
In addition to the ecological definition of certified organic crops and produce discussed here, there also exists the legal definition, uniform standards, record keeping, compliant/non-compliant materials, certification processes and many other requirements established by the National Organic Program under the authority of the United States Department of Agriculture (USDA, 2010). The ecological definition of organic farming is used in this paper.
The plant growth materials used in this study include: AGGRAND Natural Fertilizer (4-3-3), AGGRAND Kelp and Sulfate of Potash (0-0-8), AGGRAND Natural Bonemeal (0-12-0) and AGGRAND Liquid Lime; along with a leading inorganic salt-based product (24-8-16) commonly used in the consumer market.
The formulas of AGGRAND natural fertilizers consist of natural materials such as kelp, emulsified fish, lime, fulvic acid, humic acid and sulfate of potash. These materials are recognized as part of an organic cropping system. They are designed to provide necessary nutrients for the plant to grow and thrive, and to build the soil by enhancing microbial growth, thus increasing the sustainability of the system. The inorganic salt based fertilizer is designed to quickly and easily supply nutrients to the plant for optimum growth and yield (Havlin, et al 2005).
The objective of this research was to determine yield results, weight and maximum length or diameter of garden vegetables fertilized with AGGRAND fertilizers according to AGGRAND recommendations and garden vegetables fertilized with a leading inorganic fertilizer according to the manufacturer’s recommendations.
On-site planting beds were established at the AGGRAND facility in order to produce credible outdoor growth data.
In April 2010, construction began on three 20-foot by 20-foot planting beds in the open space immediately to the south of the AGGRAND facility. Each planting bed was constructed with treated timbers, stacked three high, lined with landscape fabric and fi lled with blended garden soil from Monarch Paving of Superior, Wis. The perimeter of the planting beds was surrounded by an 8-foot fence to deter animals, especially deer, from eating the plants. In addition, a wind screen made of landscape fabric was established on the east and north fence lines to minimize the effects of the cold winds from Lake Superior. The planters were filled with soil and leveled. The soil was sampled on April 20. The growth plots were completed on May 4, 2010. (See Figures 2 and 3)
Figure 1: Plot site plan
Figure 2: Planters undergoing construction
Figure 3: Completed growth plot test area
The following soil sampling procedure was followed for each planting bed to characterize each growth plot’s soil. The soil depth was 18 inches and homogenous throughout the planter. Using a soil sampling probe, soil samples were obtained from the top six inches of the planting bed at nine evenly spaced points in the area. (See Figure 4)
All soil samples were analyzed at Midwest Laboratories in Omaha, Neb., and were evaluated for percent organic matter, available phosphorus (weak and strong Bray), exchangeable potassium, hydrogen, magnesium and calcium, pH, buffer index, cation exchange capacity (CEC), percent base saturation of cation elements, carryover nitrogen as nitrate, micronutrient analysis of sulfur, manganese, boron, zinc, iron and copper, evaluation of excess lime and soluble salts. (See Tables 16 and 17 for a summary of all soil analyses obtained during this study)
A growth plot sowing plan was established to use the area most effi ciently while providing ample room for the vegetables to grow and develop, leaving enough room to water, fertilize and weed the plots. A two-foot walking path was established between the vegetable types. (See Figure 5)
Figure 4: Growth plot soil sampling
Figure 5: Growth plot planting plan
Popular hybrid varieties of vegetables were chosen for this study, with seeds established in Wisconsin or Minnesota that would produce good yields in cooler climates. The following seed and seed potatoes were planted:
• Potatoes: Variety: 04671, Superior from Jung Seed, Co. of Randolph, Wis.
• Green Beans: Variety: 01020N, Blue Lake 274 from Jung Seed, Co. of Randolph, Wis.
• Sweet Corn: Variety: 01805N, Butter & Sugar from Jung Seed, Co. of Randolph, Wis.
– Variety: 00426A, Lot 10-426-A, Legend (Determinate) from Jung Seed, Co. of Randolph, Wis.
– Variety: Celebrity® plants from Dan’s Feed Bin of Superior, Wis. Plants were approximately 8 inches to 10 inches in height.
On April 5, Legend tomato seeds were planted in five flats of 3.5-inch by 3.5-inch pots, for a total of 90 plants. The growing medium was Pro-Mix (PGX) Professional potting soil Part #0463 from Quakertown, Pa., topped with Country Cottage Sphagnum Peat Moss from Lancaster, Pa. Seeds were planted approximately 0.5 inches under the surface of the soil. Water was added to the flats by capillary action until the planting media was moist. The flats were placed into the growth area with heating mats under the flats. Fluorescent growth lamps illuminated a plastic drape over the growing area to maintain a temperature of 27.2°C (81°F) See Figure 6
• Heat Mats: (2) 20.75 inches wide x 48 inches long from Hydrofarm®, Petaluma, Calif.
• Nine-Sylvania 40W GRO-LUX F40 GRO
• Seven-VitaLite 40W DuroLite • Light Duration: 14 hours per day
• Temperature = 27.2°C (81°F) as measured by a Taylor analog dial thermometer
• Temperature and soil moisture checked every day
Initial emergence of the tomato plants occurred April 9, with a germination rate of 85.6 percent by April 12. An additional six seeds were planted the next day to replace the non-germinated seeds.
AGGRAND personnel prepared to fertilize the plants that had developed at least two true leaves — 25 milliliters (mL) of diluted fertilizer via graduated cylinder. The plants were separated, measured for length and tagged for a specific fertilizer treatment with either AGGRAND Natural Fertilizer (NOF, Lot 852-033), leading chemical fertilizer or none (control) with 28 plants in each category.
The formulation used for the AGGRAND seedling fertilization was 5 mL of Natural Fertilizer to 1,000 mL of distilled water, mixed well and placed into a laboratory squeeze bottle. Using a 25 mL graduated cylinder, 25 mL of the solution was added to each plant.
The chemical fertilizer called for 1 gram of powdered material to 946 mL of distilled water, mixed thoroughly. Each plant designated to receive inorganic fertilization received 25 mL of this solution. The fertilization and measuring process was repeated on May 3. As the plants increased in height the growth lamps were raised accordingly.
On May 10, the heat mats were turned off in the growth chamber to begin the hardening process. The temperature was reduced from 27.2°C (81°F) to 23°C (73.4°F) with the soil temperature ranging from 20.5°C (68.9°F) to 22.2°C (72°F). During the afternoon of May 17, the tomato plants were placed on a pallet and placed outdoors in a shaded area for a couple of hours to harden. This process was repeated on May 18, May 20 and May 21 for periods of 3.5 hours, 4 hours and 8.25 hours, respectively.
The best 24 tomato plants for each plot were selected and sorted on May 24. Because of their long stems, the plants were planted into holes one-foot deep. Wire supports were placed around each plant. Ambient temperature was approximately 60°F and sky was overcast, with fog. During the previous evening 0.25 inches of rain fell. Each plant was fertilized with an AGGRAND fertilizer solution of 180 mL of Natural Organic Fertilizer (NOF, 4-3-3) (measured with a 250 mL graduated cylinder), 120 mL of Natural Liquid Bonemeal (NBM, 0-12-0) (measured with a 250 mL graduated cylinder) and 60 mL of Kelp and Sulfate of Potash (NKP, 0-0-8) (measured with a 100 mL graduated cylinder) into 6,000 mL of tap water. The solution was mixed thoroughly and 1,000 mL of solution (measured with a 1,000 mL graduated cylinder) was applied to the base of each plant (AMSOIL, 2010). The same procedure occurred for the control plants using 1,000 mL of tap water for each plant. This fertilization procedure was also followed for the chemical fertilizer with a formula of 17.96 grams of powdered fertilizer (weighed using an AND FX3000i digital balance, serial number 15610355) and 6,000 mL of tap water according to the manufacturer’s instructions.
The tomato plants were evaluated on May 28 to determine the effects of transplanting into the growth plots. Eight AGGRAND plants were dead or close to death, all control plants were alive and viable for continued growth and seven of the chemically fertilized plants were dead. All tomato plants were watered with 1,000 mL of tap water. On June 1, all of the tomato plants appeared to be stressed and had soft, wet, succulent tissue. The three best-performing Legend plants of each fertilizer regime were kept and 36 Celebrity® tomato plants were purchased from Dan’s Feed Bin, Superior, Wis. Each growth plot received 12 plants, approximately 8 to 10 inches tall. Each plant was watered with 1,000 mL tap water after planting. On June 2, all tomato plants were fertilized with 1,000 mL of solution as described above.
Seed potatoes arrived during the week of April 25 from Jung Seed Company. On May 4, each seed potato was cut in half for a total of 126 pieces that contained several eyes. The cut seed potatoes were stored in a dark, cool, dry area on trays.
Figure 7: Measuring depth of hole for potatoesFigure 8: Method of fertilization for potato plots
On May 18, the seed potatoes were planted eight inches deep and covered with with three inches of soil. Four rows of seven plants were planted in each timber box. (See Table 1 for detailed planting data.) Seed potatoes were fertilized with an AGGRAND solution of 180 mL of Natural Organic Fertilizer (measured with a 250 mL graduated cylinder), 120 mL of Natural Liquid Bonemeal (measured with a 250 mL graduated cylinder) and 60 mL of Kelp and Sulfate of Potash (measured with a 100 mL graduated cylinder) into 6,000 mL of tap water. The solution was mixed thoroughly and 1,000 mL of solution (measured with a 1,000 mL graduated cylinder) was applied to the base of each plant. (AMSOIL, 2010) The control plants received only 1,000 mL of tap water per plant. The same fertilization procedure was followed for the chemical fertilizer with a formula of 17.96 grams of powdered fertilizer (weighed using an AND FX3000i digital balance, serial number 15610355) and 6,000 mL of tap water. (See Figures 7 and 8)
Figure 6: Newly-planted tomato seeds
Sweet corn and bush beans were sowed May 25. Four rows of each plant per fertilizer type were established. Seed was placed about one inch beneath the soil surface, covered and fi rmly packed by hand. (See Table 1 for planting specifi cs and Figures 9 and 10 below:)
Each row of the AGGRAND plot was fertilized with a solution of 180 mL of Natural Fertilizer (measured with a 250 mL graduated cylinder), 120 mL of Natural Liquid Bonemeal (measured with a 250 mL graduated cylinder) and 60 mL of Kelp and Sulfate of Potash (measured with a 100 mL graduated cylinder) and 6,000 mL of tap water. The solution was mixed thoroughly and each row of corn and beans was fertilized using a sprinkler can to evenly distribute the solution along the length of the row (AMSOIL, 2010). The control plants received 6,000 mL of tap water per row. The same fertilization procedure was followed for the chemical fertilizer with a formula of 17.96 grams of powdered fertilizer (weighed using an AND FX3000i digital balance, serial number 15610355) and 6,000 mL of tap water. (See Figures 11 and 12 below)
Figure 9: Corn seed spacing
Figure 10: Bean seed spacing
Figure 11: Row fertilization technique
Figure 12: Fertilizing with leading inorganic
By June 2 all plots were seeded, and all tomato plants were in place according to Table 1.
Table 1: Planting summary
After all plants and seeds were established, precipitation, routine weeding, cultivating and watering were monitored and are summarized in Table 2.
Table 2: Plot maintenance summary
Tables 3, 4, 5 and 6 summarize fertilizer applications and general formulas used for each plot. Percent indicates the amount of fertilizer to water as specifi ed in tables 7, 8 and 9. Date of application shown in red.
Table 3: Planting - soiling application
Table 5: Third application — foliar feeding
Table 6: Fourth application — foliar feeding
For beans, corn and potatoes, 6,000 mL of chemical fertilizer mix were applied with a watering can per row. For tomatoes, 1,000 mL (measured with a 1,000 mL graduated cylinder) was applied per plant. Control applications followed the same timing and volume as the chemical fertilizer and were treated with tap water through the growing season. Several AGGRAND fertilizer applications did not follow the prescribed schedule exactly because of frequent rains. (Table 2) The chemical fertilizer was applied at regular two-week intervals after the initial planting and establishment of the plants. Tables 7, 8 and 9 summarize the fertilizer formulations employed on the growth plots.
Table 7: AGGRAND fertilizer application timing and formulations
(1) AGGRAND Natural Organic Fertilizer (4-3-3)
(2) AGGRAND Natural Bonemeal (0-12-0)
(3) AGGRAND Natural Kelp and Sulfate of Potash (0-0-8)
(4) AGGRAND Natural Liquid Lime
Table 8: Leading chemical fertilizer application timing and formulations
Table 9: Control plot fertilizer application timing and formulations
During the late afternoon of June 24, a heavy thunderstorm produced hail and damaged many of the plants in the growth plots. Fortunately, the vegetables were not flowering at this time and long-term damage was held to a minimum. See Figures 13, 14, 15, and 16.
Figure 13: Damaged sweet corn
Figure 14: Damaged tomato plant
Figure 15: Damaged green bean plants
Figure 16: Damaged potato plants
On October 7, after all crops had been harvested and prior to tilling each planting bed, soil samples were taken from each crop area in each bed. Samples from nine evenly spaced points were obtained (Figure 17), mixed and forwarded to Midwest Laboratories for analysis to determine percent organic matter; available phosphorus (weak and strong Bray); exchangeable potassium, hydrogen, magnesium and calcium; pH; buffer index; cation exchange capacity (CEC); percent base saturation of cation elements; carryover nitrogen as nitrate; micronutrient analysis of sulfur, manganese, boron, zinc, iron and copper; and evaluation of excess lime and soluble salts. A total of 12 post-harvest samples were tested; all soil samples are summarized in Tables 16 and 17.
Figure 17: Fall 2010 soil sampling
Evaluation of tomato performance not only included the amount and size of fruit formed, but also plant growth rate and vigor of the Legend plants grown from seed. As already stated, initial emergence of the tomato plants occurred on April 9 and on April 12, the germination percentage was determined to be 85.6 percent.
On April 19, plants were measured for height and separated into three groups of 29 destined for the three fertilizer treatments. This data was recorded and averaged. Fertilizer was applied on April 19, and on May 3, the height of each plant was re-measured with the data being averaged for each fertilizer type. Figure 18 summarizes seedling height per fertilizer.
Figure 18: Tomato start growth
The image in Figure 19 was taken on May 10 to demonstrate the relative height and vigor of the tomato plants with differing fertilization systems. The AGGRAND - treated plants appear taller than both the control and chemically fertilized plants, while the AGGRAND and chemically fertilized plants have more abundant and greener foliage than the control plants.
Figure 19: Tomato plants prior to being transplanted
Tomato seedlings were transplanted the last week of May because of the potential for frost and to provide ample time to acclimate to outdoor growing conditions. As seen in Figure 19, the plants were of adequate size to be planted in the garden plots; however, the delay in transplanting caused the plants to become spindly, with the plant tissue becoming soft and succulent. Figure 20 shows the tomato plants during the hardening process and the weakness of the plant stems.
Figure 20: Tomato plants during the hardening process
After planting, the majority of the starts showed substantial stress, died or were dying. Each plot retained three Legend tomato plants and each had 12 Celebrity tomato plants added. All 15 plants in each growth plot survived and produced fruit.
Over the growing season, the AGGRAND - fertilized plants showed more vigor and were larger overall than the chemically fertilized or control tomatoes. On July 13, plant height and relative vigor were ranked on a one to five scale where five was the best and zero was a dead plant. AGGRAND Fertilizer Specialist Walter Sandbeck measured vigor by evaluating leaf color (intensity of green), leaf number, height, flowering, plant firmness and stem diameter. The AGGRAND plants, even though suffering from hail damage, were ranked with vigor values of five and ranged from 12 inches to 23 inches in height. All plants were blooming and several were in post-bloom stage. The chemically fertilized plants were given a vigor rank of four, with one plant having a rating of three. The plants had more maturity variation than the AGGRAND plants, with some in pre-bloom stage and three with small fruit emerging. Height of these plants ranged from 12 inches to 20 inches. Control plants were visually less appealing than AGGRAND or the chemically fertilized plants. Overall vigor was ranked between three and four, with half of the plants in pre-bloom stage and the remaining in bloom. Two control plants had one 0.375 inch and one 0.675 inch tomato per plant. Plant height ranged from 10 inches to 20 inches.
On August 25, the first tomatoes were harvested. The following criteria were developed to evaluate the performance of each plot: 1) Tomatoes should be orange or red on the vine at the time of harvest. 2) Fruit on the ground will be counted and measured, even when green. 3) Will harvest all, including green fruit, when a freeze is imminent. 4) Determine number, weight and maximum diameter for each tomato per plot. 5) Determine degrees Brix of one tomato from each plot per picking day.
Figure 21: Tomatoes at various ripening stages
Figure 22: Measuring maximum tomato diameterEach tomato was weighed using an AND FX3000i digital balance, serial #15610355, and the maximum diameter was measured with a Mitutoyo Corporation Digimatic Caliper, Model CD-6” CSX, Serial #07435188. The diameter was measured perpendicular to the axis of the stem and center core of the fruit. See Figure 22.
Tomatoes fertilized with the AGGRAND fertilization system produced fruit in greater numbers which equated to more total weight when compared to plants that were fertilized with the chemical product. As expected, the control plants fared the worst as far as quantity, but produced a slightly larger and heavier tomato. Average sugar content as measured by degrees Brix was slightly lower for the AGGRAND-treated tomatoes when compared to tomatoes grown in the other plots. Differences in quality are noticed when at least 2 to 4 degrees Brix between fruit samples are taste-tested (International Ag Labs, 2010).
Table 11: Final tomato results
On June 1, most of the sowed bean seeds had germinated; some seeds were washed away or moved within the planting row due to heavy rains. Total germination of the AGGRAND plot was 83 percent; total germination for both the chemical fertilizer and control plots was 80 percent.
On July 13, the green bean plants were measured and relative vigor rankings were determined on a one to five scale where five was the best and zero was a dead plant. The AGGRAND - fertilized plants, showed some signs of hail damage, but the majority of them (over 60 percent) were given a rank of five, were flowering and were 8 inches to 12 inches tall. The remainder of the plants ranked from one to four, with the majority ranking three to four with dark green foliage and little or no pest damage. The plants fertilized with the leading chemical product were healthy with little pest damage. Eighty percent received a vigor ranking of four, with many of the plants flowering. Average height was six inches to eight inches, and the foliage was lighter green than the AGGRAND - fertilized plot. There were few plants ranked three and two, but most plants that were not ranked a four were ranked as a small plant (one). Control plants were visually less appealing than the AGGRAND or the chemically fertilized plants. The foliage was lighter green; over 88 percent of the plants were given a vigor ranking of three; and a number of plants were blooming. All plots were producing 0.5-inch to one-inch beans on July 20. See Figure 23.
Figure 23: Green bean plant comparison
Commenced harvest on July 26 by picking beans that were at least four inches long. Attempted to harvest every Monday, Wednesday and Friday when weather conditions were favorable. On August 30, the harvesting was deemed completed when the plants yielded very few fruit and were degrading. See Figure 24.
Figure 24: Green bean harvest
The AGGRAND fertilized plot produced more, larger, heavier beans than the other growth plots. Due to the overall high fertility of the soil, the yields were very good for all plots. Average sugar content, as measured by percent Brix, was slightly lower for AGGRAND when compared to the other growth plots; this difference, however, would not be discernible by taste.
Table 12: Final green bean results
As previously stated, potatoes were planted on May 18, before all other crops. Growth rate and plant vigor comparisons were conducted when the plants started to emerge around June 1. Rapid plant growth occurred from June 1 to June 6. Figure 25 compares plant development per fertilizer/growth plot.
Over the growing season, the AGGRAND potatoes showed more vigor and were larger overall than the chemically fertilized or control plants. On July 13 the plants were measured and relative vigor rankings were determined on a one to five scale where five was the best and zero was a dead plant. Again, AGGRAND plants, even though showing some signs of hail damage, were given a ranking of five and were approximately 24 inches tall. Six plants were blooming. The chemically fertilized plants were given a vigor ranking of four. Fifty percent of them were blooming and they were between 12 inches and 18 inches tall. Control plants were visually less vigorous than the AGGRAND or the chemically fertilized plants. Overall vigor was ranked at three, with 11 out of the 28 plants blooming. Plant height ranged from 10 inches to 16 inches. Plant height and vigor had less variation within each plot, but showed distinct difference from plot to plot. Due to the excess moisture, as the growing season progressed, the plant leaves turned a brownish green and curled. By the end of August, die-back was obvious in all plots, but the AGGRAND - fertilized potato plants produced new, prolific shoots and leaves.
Figure 25: Potato plant comparison
On September 30, harvest was conducted when the control and chemically fertilized plants had essentially died back. See Figure 26.
Figure 26: Potato harvest
Figure 27: Measuring maximum potato length
Yield comparison was determined by weighing each potato using an AND FX3000i digital balance, serial #15610355 and measuring their maximum length (See Figure 27). Sugar content was determined with an Atago ATC-1E Hand Refractometer that measured degrees Brix 0 to 32. See the yield summary in Table 13.
Table 13: Final potato results
Figure 28Potato plots fertilized with the AGGRAND fertilization system produced greater numbers and naturally equated to more total weight when compared to the plots fertilized with the chemical product. As expected, the control plants fared the worst as far as quantity, but produced a slightly larger and heavier potato. Average sugar content as measured by degrees Brix was slightly lower for the control when compared to the other growth plots, but this difference would not be discernable by taste. AGGRAND and control programs yielded potatoes with less scabbing. See Figure 28.
On June 1, most of the sowed corn seeds had germinated; however, heavy rains forced some to move within the planting row and required they be reset at the proper depth and spacing. Total germination of the AGGRAND plot was 100 percent; one seed failed to germinate in the chemical fertilizer plot and three seeds failed to germinate in the control plot.
On July 13, the corn plants were measured and relative vigor rankings were determined on a one to five scale where five was the best and zero was a dead plant. All AGGRAND - fertilized plants were given a ranking of five and ranged from 10 inches to 28 inches tall. The plants fertilized with the leading chemical product were healthy, with 100 percent receiving a vigor ranking of four, ranging from 10 inches to 20 inches tall and a few were multi-stemmed. The foliage was lighter green than the AGGRAND - fertilized plants. Control plants were noticeably light green in color when compared to the AGGRAND or the chemically fertilized plants. Overall vigor was given a ranking of three with the plants ranging in height from 8 inches to 18 inches—noticeably shorter than the AGGRAND and chemically fertilized corn.
Additional observations were conducted regarding the formation of tassels and corn cobs throughout the growing season. On July 20, the AGGRAND corn plants were the only producers of tassels; 31 percent of the plants were at this stage of development. Investigation on August 3 revealed that 11 AGGRAND corn plants were forming cobs, while one chemically fertilized plant was observed at this state, and no control plants were forming distinct cobs at this time. The AGGRAND - fertilized corn was much more developed than the other plots.
Harvest was conducted on September 8 to avoid the corn becoming overdeveloped and starchy. The cob size was monitored carefully to provide the best-tasting product possible.
Figure 29: Ear size comparison
Figure 30: Corn harvest
Parameters measured include cob weight using an AND FX3000i digital balance, serial #15610355, cob length, total weight per row, total weight and number per fertilizer type along with average kernel count of the fi ve largest cobs from each row, and average cob length and weight. Maximum cob length was determined by using the apparatus in Figure 31.
Figure 31: Measuring maximum corn cob length
Corn fertilized with the AGGRAND fertilization system produced a greater number of total and edible ears that had a greater number of kernels than the chemically fertilized plants. Average ear length and weight were also greater for the AGGRAND plot. Figure 29 shows the ear size comparison from row 1 (south) of each plot. Note that the AGGRAND plot had 18 ears full of kernels, while the chemical and control plots had nine and eight full cobs, respectively. The best-quality ears are shown in Figure 30. As expected, the control plants with no fertilizer being added fared the worst as far as quantity and quality. The control corn stalks were brittle and easily broken, while the AGGRAND stalks were the strongest. The chemically fertilized corn had the only smut on the ears (3); one small smut spot on an AGGRAND stalk was evident. Row four (north) of all growth plots had a few ear worms.
See Figures 34 and 35 for harvest summary for all crops and fertilizer systems.
Figure 34: Yield comparison by number
Figure 35: Yield comparison by number
As previously mentioned, soil sampling and analysis was conducted after the soil was incorporated into the planters and after harvest. Nine samples of each plot were taken in the spring, and nine samples per crop per planter were obtained in the fall after harvest.
See Figures 36 and 37.
Figure 36: Soil analysis probe/bucket
Figure 37: Soil sample, 6 inches deep
Table 16: Soil analysis aummary
Table 17: Soil analysis summary
With the addition of AGGRAND fertilizers, soil fertility was maintained in spite of the plants removing the nutrients throughout the growing season and in some cases it improved over the growing months compared to the chemically fertilized and control plots. Most notable were the increases in the levels of phosphorus, potassium and magnesium. The dramatic increase in phosphorus could be attributed to the addition of the AGGRAND fertilizers, while the other plots saw only a marginal increase. These marginal increases could be due to seasonal effects of increased biological activity. In all plots, some micronutrient, nitrate levels and soluble salts decreased from the spring to the fall harvest. The reduction could be attributed to plant uptake and to nutrient leaching associated with watering and rain movement through the soil layer.
This study shows that the AGGRAND fertilization program, as outlined in The Gardening Guide (AMSOIL, 2010), increased yield in terms of vegetable number and total harvest weight when compared to the leading chemical fertilizer for these garden vegetables and soil type. Average weight and size of the green beans and corn were higher, while the overall size of the tomatoes and potatoes was slightly smaller, but not significant.
The leading chemical product used in this study is easy to apply. It is comprised of soluble salts that rapidly dissolve in water. Application frequency is also straightforward by the simple addition of the product every two weeks during the growing season. The AGGRAND system enhances the soil environment, but requires the grower to monitor plant development, flower bloom and fruit growth for timely fertilizer applications, which is directly correlated to improved yield.
The incorporation of nutrients into plants from the soil and fertilizer has been studied for decades and is well documented. In order to transport nutrients to the plant cells, mineral compounds must be dissolved in water to form ions. There are three ways ions move to the root. One is by root interception or simple contact of the ionic solution with the root. As roots grow and expand there will be an increasing chance that soil water containing nutrient ions will interact with a root and its hairs, enabling the plant to grow at an increasing rate. Second, when the plant is transpiring water from the leaves, water is simultaneously being drawn through the stem and root, pulling water and nutrients from the soil. This mechanism is called mass flow. Last, diffusion occurs when nutrients are transported from an area of high ion concentration away from the root, toward the root and an area of low ion concentration (due to the plant’s intake of the nutrient ions) (Havlin, et al 2005). The mechanisms employed to transport the nutrients are the same for the leading chemical fertilizer, AGGRAND fertilizers, and existing soil nutrients without supplemental inputs such as the control plot.
Nitrogen, phosphorus and potassium ratios (N,P,K) of the fertilizers employed in this study were 4-3-3, 0-12-0, and 0-0-8 for the AGGRAND program, and 24-8-16 for the leading chemical fertilizer. Summing the fertilizer applications performed throughout the study, one would expect the 24-8-16 product to produce more vegetables due to the greater amount of nutrient ions introduced into the soil. With all plots being the same, with the exception of fertilizer inputs, there appear to be factors that enhanced the productivity of the AGGRAND vegetable plot beyond the simple addition of these elements.
There are several factors that may have contributed to the increased production of the AGGRAND plot over the chemical fertilizer-grown vegetables. One is the treatment of the organic matter and the associated microorganisms in the soil.
Organic matter is one of the most neglected and important components of the soil due to its seasonal release of plant nutrients. Soils and crops can survive, even when mismanaged, if suffi cient organic matter is present (Albrecht, 1996). According to Kinsey and Walters (2009), “Without an active organic matter system in the soil you cannot grow any crop at all, no matter how much nitrogen, potassium, and phosphorus you add.”
The soil used in this study had ample, if not ideal amounts of organic matter, but organic matter in its non-decomposed form has little impact on the soil’s nutrient level. Many times organic matter and humus are considered synonymous, but in reality humus is the main driver of holding and supplying nutrients to the plant. Humus is decomposed organic matter that is the main source of naturally available nitrogen, phosphorus, sulfur, boron and zinc (Kinsey and Walters, 2009). Active organic matter, or humus, along with other soil nutrients is produced by the activity of organisms in the soil. Soil organisms ranging in size from the smallest bacteria to earthworms break down organic residues, consume other organisms and enrich the soil by their movement and death (Soil and Water Conservation Society, 2000). AGGRAND fertilizers incorporate fish, kelp, blood meal and other carbon sources that provide food for soil organisms, resulting in increased microbial activity, all while supplying necessary inorganic nutrients. The chemical fertilizer used in this study does not contribute organic compounds or carbon to the soil organisms. In fact, studies show that inorganic fertilizers, when used alone, negatively impact microbial populations. The use of organic fertilizer increases the nutrient level, the “productive potential” and microbial activity of the soil (Nakhro and Dkhar, 2010). Again, with the increase in organic and sustainable farming practices a greater awareness has developed regarding the use of chemical fertilizers and pesticides. Among the reasons chemical fertilizers are prohibited in an organic agricultural system is their negative impact on microorganisms and earthworm populations (Bolen, et.al., 1996). According to Mäder, et.al. (2002), who conducted a 21-year study in central Europe comparing organic to conventional farming systems, “organically managed soils exhibit greater biological activity than the conventionally managed soils.” Their study also revealed a 1.3- to 3.2-fold increase in the number of earthworms in the organic system as compared to conventionally farmed plots (Mäder, et.al., 2002).
Humic substances, which include humic and fulvic acids are derived from decomposed soil organic matter or peat and range from yellow to a dark brown to black in color (Jones, Jr., 2005, Rauthan and Schnitzer, 1981). The physical and chemical properties of these compounds are derived from the environment in which they were formed. Humic and fulvic acids are formulated into AGGRAND Kelp and Sulfate of Potash (NKP) and AGGRAND Natural Fertilizer (NOF), which may account for the increased yield when compared to the inorganic fertilizer. Studies show that humic and fulvic acids promote growth and increased microbial activity within the soil. Recent research has revealed that humic acids play a definite role in influencing mineral nutrition, holding micronutrient metal ions, and the macronutrients nitrogen, phosphorus and potassium. These compounds also influence plant hormones, antioxidant status and photosynthetic capacity (Schmidt and Zhang, 1998). The inorganic product only provides nutrients via the dissolution of salts into ions.
In the early 20th century it was found that humic substances influence plant hormonal activity and increased mineral ion solubility, specifically iron. Years of research has revealed that humic compounds enhance turf root development, and tree seedlings have a propensity to increase the absorption of key nutrients such as nitrogen, phosphorus, calcium, zinc, iron, magnesium, potassium and copper. Specifically, fulvic acid forms stable compounds containing iron, and enhances the uptake of this essential element through the plant from the roots system to the shoots. It has also been found that foliar spraying humic substances on the plant increase the chlorophyll content of the leaves, helping prevent chlorosis in corn plants by the increased uptake of magnesium and iron and making the plants more resistant to environmental stresses and disease (Schmidt and Zhang, 1998). Rauthan and Schnitzer (1981) reported that concentrations of fulvic acid ranging from 100 parts per million (ppm) to 300 ppm increased the growth and development of cucumber plants, above and below ground, but also found, at low concentrations, increased algal and microbial growth within the soil. In addition, the number of flowers was increased which has a direct correlation to yield.
Kelp, commonly known as seaweed, has been used for human consumption and as a soil amendment since the advent of civilization. Extracts of seaweed are still used in agriculture and detailed research on the benefits of these extracts has been available since the early 1950’s (Thirumaran, et.al., 2009, Senn, 1987). Commercially manufactured seaweed extracts for agricultural use have been employed for at least forty five years (Reitz and Trimble, 1996).
Numerous studies show that potassium, key micronutrients, plant hormones, growth regulators/promoters, carbohydrates, proteins and vitamins are supplied by kelp species such as the Ascophyllum nodosum that is formulated into AGGRAND Natural Fertilizer and AGGRAND Kelp and Sulfate of Potash (Thirumaran, et.al., 2009, Senn, 1987). Field trials show that foliar applications of seaweed extract to bananas increase fruit productivity and shorten the time to shoot development. Kelp soil applications resulted in increased crop yields of a diversity of crops including oranges, potatoes, tomatoes, sweet corn and peppers. Improved shelf-life and resistance to drought and disease are also realized when the proper amounts of kelp are added to a fertilization program (Senn, 1987). Some experts report greater leaf mass compared to control plants when studying Ascophyllum nodosum extracts on Henderson Bush lima beans (Reitz and Trumble, 1996).
Finally, test plot soil fertility will be monitored from year to year. From the soil analyses obtained to date, AGGRAND fertilizers appear to contribute to soil fertility, or directly provide the plants with enough nutrients to sustain healthy growth. More study must be done to determine the long-term effects of fertilizer applications to these plots.
Albrecht, W.A. (1996). The Albrecht papers. (Vol. 1). Metairie, LA: Acres U.S.A.
AMSOIL INC. (2010). The AGGRAND gardening guide. G1292. Superior, WI: AMSOIL, INC.
Bolan, N.S., L.D. Currie, and S. Baskaran. (1996). Assessment of the influence of phosphate fertilizers on the microbial activity of pasture soils. Biol. Fertil. Soils. 21: 284-292.
Havlin, J.L., J.D. Beaton, S.L. Tisdale, and W.L. Nelson. (2005). Soil fertility and fertilizers, an introduction to nutrient management. Upper Saddle River, NJ: Pearson Education.
International Ag Labs, Inc. (2010). High brix chart. Available at: http://www.highbrixgardens.com/pdf/brixchart. pdf
Jones, Jr., J.B. (2005). Hydroponics a practical guide for the soilless grower. Boco Raton, FL: CRC Press.
Kinsey, N. and C. Walters. (2009). Hands on agronomy. Austin, TX: Acres U.S.A.
Mäder, P., A. Fliebach, D. Dubois, L. Gunst, P. Fried, and U. Niggli. (2002). Soil fertility and biodiversity in organic farming. Science. 296: 1694–1697.
McLoughlin, A.J. and E. Küster. (1972). The effect of humic substances on the respiration and growth of microorganisms. Plant and Soil. 37: 17-25.
Nakhro, N., and M.S. Dkhar. (2010). Impact of organic and inorganic fertilizers on microbial populations and biomass carbon in paddy field soil. Journal of Agronomy. 9 (3): 102-110
National Stone Association. (1986). Aglime fact book. Washington, D.C.: National Stone Association.
Organic Trade Association. (2010). Industry statistics and projected growth. Available at: http://www.ota. com/organic/faq.html
Rauthan, B.S. and M. Schnitzer. (1981). Effects of a soil fulvic acid on the growth and nutrient content of cucumber (Cucumis sativus) plants. Plant and Soil. 63: 491-495.
Reitz, S.R., and J.T. Trumble. (1996). Effects of Cytokinin-containing seaweed extract on Phaseolus lunatus L.: influence of nutrient availability and apex removal. Botanica Marina. 39: 33-38.
Schmidt, R.E. and X. Zhang. (1998). How humic substances help turfgrass grow. Golf Course Management. 66(7):65-67.
Senn, T.L. (1987). Seaweed and plant growth. Clemson, SC: Senn.
Soil and Water Conservation Society. (2000). Soil biology primer. Ankeny, IA: Soil and Water Conservation Society.
The Rodale Institute. (2010). History of the Rodale Institute. Available at: http://www.rodaleinstitute.org/ about_us#history
Thilmany, D. (2006). The U.S. organic industry: Important trends and emerging issues for the USDA . Colorado State University Agribusiness Marketing Report ABMR 06-01.
Thirumaran, G., M. Arumugam, R. Arumugam, and P. Anantharaman. (2009). Effect of seaweed liquid fertilizer on growth and pigment concentration of Abelmoschus esculentus (I) medikus. American- Eurasian Journal of Agronomy. 2(2): 57-66.
United States Department of Agriculture. (20100. National Organic Program. Available at: http://www. ams.usda.gov/AMSv1.0/nop
University of Wisconsin - Extension. (2010). What is organic farming? Available at: http://www.extension. org/article/18655