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2013 AGGRAND Vegetable Productivity Study

Abstract

For the past four growing seasons AGGRAND has performed growth studies comparing yield and soil quality as a result of using AGGRAND and competitive fertilizers designed for the consumer and large-scale grower market. This year’s study evaluated sweet-corn and green-bean yield. The AGGRAND fertilization system significantly outperformed a leading competitive Organic Materials Review Institute (OMRI) listed product. In addition, soil nutrient levels and respiration continued to improve in the AGGRAND growth plot.

 

Introduction

This annual study reports the yield and soil-building benefits of using AGGRAND fertilizer products, and their timed applications. On a different level, it is important to understand why using the AGGRAND system is good stewardship for soil and water resources.

 

One of the most glaring problems of excessive use of synthesized chemical fertilizers is the expansion of oceanic dead zones throughout the world. Dead zones are hypoxic, or low-oxygen, areas in the world’s oceans and large lakes that lack the oxygen needed to support most marine life, according to the National Oceanic and Atmospheric Administration (NOAA). These hypoxic zones are formed when run-off from agricultural fields containing excessive nitrogen and phosphorus from chemical fertilizers and other industrial and domestic wastes is introduced into the watershed.

 

North American dead zones are found in Lake Erie, the lower St. Lawrence River and off of Cape Perpetua, Ore. They also are found in the Baltic Sea, South America, China, Japan and Australia. Most dead zones are associated with areas of heavy agricultural and industrial activity. Americans are most familiar with the Gulf of Mexico dead zone that is west of the Mississippi Delta and over the continental shelf near southern Louisiana and Texas. (Osterman, 2006) See Figure 1

Figure 1

Dead Zone in Gulf of Mexico

(Courtesy of N.N. Rabalais, Louisiana Universities Marine Consortium)

Americans are most familiar with the Gulf of Mexico dead zone that is west of the Mississippi Delta.

Excess fertilizer runoff from the upper Mississippi, Missouri, Arkansas and Ohio rivers finds its way to the Gulf of Mexico, which stimulates algal blooms that eventually die and are consumed by bacteria. (Figure 2) Bacterial decomposition results in the consumption of large amounts of dissolved oxygen causing fish and other creatures to move out of the area. Meanwhile, some creatures simply die, creating a dead zone. The diminished shrimp population and deteriorated spawning areas harm the ecosystem, as well as the fishing and tourist industries in these regions.

Figure 2

Mississippi River Watershed

(Courtesy of the United States Corps of Engineers)

mississippi river delta, missouri river basin, ohio river basin,

Excess nutrients in the Gulf of Mexico are not a new phenomenon. Since 1985 researchers have monitored the oxygen content in the Gulf of Mexico and show that hypoxia has increased during that time. Historical oxygen levels also are being investigated through samples of the ocean’s bottom core. The samples reveal variations in oxygen levels since 1850, mostly likely from large areas of upriver land clearing. Overall oxygen levels have showed a steady decline from 1950 to 2003. (Osterman, 2006)

 

Biological systems can stem the tide of hypoxia, but when excess nitrate and phosphorus are continually introduced, these systems are eventually overwhelmed. AGGRAND products are natural soil amendments and can play an important role in decreasing nutrient runoff. AGGRAND fertilizers are applied in discreet amounts, allowing the natural systems to process the material into the soil or directly into the plant. Managing a natural, organic or AGGRAND system takes more care and attention to detail, but it helps provide a better long-term solution to the environmental problems associated with traditional agricultural methodology.

 

AGGRAND natural fertilizers and soil amendments are formulated with natural products such as emulsified fish, kelp, limestone, fulvic acid, humic acid and sulfate of potash. These materials are recognized as part of a sustainable cropping system designed to provide the necessary nutrients for plants to grow and thrive. They also enhance microbial growth to build the soil. (Albrecht, 1996, Kinsey, 2009, National Stone Association, 1986, Senn, 1987). The competitive organic fertilizer used in this study is formulated to deliver similar benefits but appears to be less highly-formulated than AGGRAND products. The following fertilizers and soil amendments were employed in this study:

 

AGGRAND Natural Fertilizer (4-3-3), Product Code: NOF

AGGRAND Natural Kelp and Sulfate of Potash (0-0-8), Product Code: NKP

AGGRAND Natural Liquid Bonemeal (0-12-0), Product Code: NBM

AGGRAND Natural Liquid Lime, Product Code: NLL

 

OMRI-Listed, (3-3-0.3) competitive fertilizer, primarily used by larger growers because of its low cost. The product is distributed across the United States in a variety of package sizes, including one-gallon containers. According to package recommendations, the application rate for outdoor plants is 1 ounce per gallon of water. This product is composed of hydrolyzed fish and is stabilized with phosphoric acid, an available phosphorus source for plants.

 

This study aimed to determine yield by weight and number of garden vegetables fertilized with the AGGRAND program as outlined in the AGGRAND Gardening Guide (AMSOIL, 2013) compared to a plot fertilized with a competitive organic fertilizer by following the manufacturer’s mix ratios and application protocols. In addition, soil evaluations were continually executed to determine nutrient shifts for each system and the impact of each fertilization system.

Materials and Methods

 

Soil Sampling

 

On April 29, prior to tilling, soil samples were obtained from the top 4 inches of each planting bed at nine evenly spaced points using a soil sampling auger. See Figure 3.

Figure 3

Soil Sampling Plan

soil samples were obtained from the top 4 inches of each planting bed

The soil samples were shipped to Midwest Laboratories of Omaha, Neb. for analysis specifying the “S3C” package. The analysis included evaluation of 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, and carry-over nitrogen as nitrate. Additionally, micronutrient analysis of sulfur, manganese, boron, zinc, iron and copper, and evaluation of excess lime and soluble salts were part of the detailed analysis. See Graphs 7 -10 in the Results section for a summary of all soil analyses obtained during this study.

Plot Plan

Prior to planting, a growth-plot sowing plan was established to use the area most efficiently by providing ample room for the vegetables to grow and develop, while leaving enough room to water, fertilize, and weed the plots. A 2-foot walking path was established between the vegetable types. See Figure 4.

Figure 4

2013 Growth Plot Plan

Tilling the plots was delayed for more than a month because of a number of late-season snowstorms. On June 4, all plots were tilled with soil temperature (Davis, Part # 6470) and moisture (Watermark®, Part # 6440) sensors reset in the AGGRAND, control and competitor plots. Sensors were placed at a depth of 12 inches (30.5 cm) between the inner first and second rows of each sweet-corn plot. These sensors were connected to a solar transmitter (Davis, Part # 6345), and transmitted data to the weather console and personal computer located in the AGGRAND laboratory. See Figures 5 and 6.

Figure 6

Moisture and Temperature Sensor Location in Corn Plot

moisture sampling, temperature sensor, corn plot

Figure 5

Preparations for Planting

temp sensor, moisture sensor

To reduce wind, and maintain air and soil temperatures in the planting area, a 6-foot-wide windscreen was attached to the fence around the perimeter of the site. SunBlocker Premium, 60 percent Shade cloth was obtained from Farm-Tek Supplies, Dyersville, Iowa, (Part #103764).

 

The vegetables in this study are popular hybrid and organic varieties, with seed established in cooler climates to produce good yields.

 

The following seed were planted in this year’s study:

 

• Hybrid Sweet Corn: Trinity (F1) (Natural II) (Zea mays), Johnny’s Seed Product ID: 2113B

Website: www.johnnyseeds.com/p-7366-trinity-f1-natural-ii.aspx

 

• Bush Snap Bean: Provider (OG) (Phaseolus vulgaris), Johnny’s Seed Product ID: 10G

Website: www.johnnyseeds.com/p-6477-provider-og.aspx

 

Soil Respiration

Carbon dioxide respiration is a measure of the bacterial action within the soil that leads to mineralization of key soil nutrients such as nitrogen and phosphorus and is an indicator of soil health. (Haney, 2008) This parameter can be determined in a number of ways. This study employed the Solvita Soil Respiration Kit offered by Woods End Research of Mount Vernon, Maine. (United States Department of Agriculture, 1999, Haney, 2008) In 2010, AGGRAND obtained the Solvita respiration measuring system, which included a Solvita Digital Color Reader, test jars and color-metric paddles (Part # DCR-soil).

 

Soil samples from each plot were obtained before and after the growing season. One hundred grams of soil were collected from the AGGRAND, control, and competitive plots and placed into a Boekel Scientific convection oven (Model: 132000, Serial #: 022503749) at 47.6°C (116°F) to dry over night. The next day, 40 grams of soil from each plot were weighed with an AND FX3000i digital balance (Serial #: 15610355) and placed into small plastic beakers lined on the bottom with filter material. The beakers were placed into a glass jar and 25 mL of distilled water was added to the soil-filled beakers. Each beaker received a Solivita® CO2 test paddle into each jar and sealed with a lid. Samples were measured using Solvita Soil Respiration paddles (Serial # 260113S) Exp: 9/2014 with Solvita Digital Color Reader Model S100. See Figures 7 through 9.

Figure 7

Adding Distilled Water into Soil

distilled water in soil sample

Figure 8

Sample Jar, Soil & Paddle

solvita, low-level CO2 detector for soils and grains, woods end laboratories

Figure 9

Color Reader

The soil respiration results are summarized in Table 14 and Graph 8 in the Results Section.

 

 

Weather Data

The documentation of weather data and comparison with historical data is essential to convey the conditions the plants encounter throughout their growth and development. Weather data was collected, archived and reported throughout the 2013 growing season. Up to 31 parameters were evaluated by the weather station and associated software. Figure 10 shows the weather station data-collection apparatus. Figures 11 and 12 illustrate the data output at the host computer.

Figure 10

Weather station

photo of wether station, weather sensing equipment

Figure 11

Current weather data

current weather at aggran test plot, wether data

Figure 12

Display of outdoor temperature and precipitation for one year

Display of outdoor temperature and precipitation for one year

Weather observations for the previous study years and the 2013 growing season are summarized in Graphs 3 through 7 in the Results section .

 

 

Sweet Corn and Green Bean Planting

Sweet corn was planted on June 11 according to the planting detail at a depth of 1 to 2 inches. On June 12, green beans were sown. Bean seeds were planted at a depth of 1 inch with row and seed spacing as shown in Table 1. After planting, each row was fertilized or watered as described in the fertilization plan. (Figure 13 and Table 3)

Figure 13

Planting and Fertilizing Sweet Corn

Planting and Fertilizing Sweet Corn
freshly planted, fertilized and watered, sweet corn

Table 1

Planting detail

Table 2

Growth Plot Maintenance

Date                                                          Activity

 

4/29/2013                         Obtained soil samples at nine evenly spaced points in all plots.

                                         Installed new moisture sensor in the competitive plot.

 

6/4/2013                           Tilled all plots; lined specific growth plots and walkways.

 

6/11/2013                         Planted 48 seeds of corn per row; will thin according to planting plan.

                                         Fertilized corn seed according to fertilization plan.

 

6/12/2013                         Planted 80 seeds per row of bush beans; thin according to planting plan.

                                         Fertilized bush beans seed according to fertilization plan.

 

6/17/2013                         Approximately 50 percent of the corn seed has germinated; no beans germinated.

 

6/19/2013                        Corn is about 95 percent germinated; beans pushing up soil.

 

6/25/2013                        Fertilized corn in competitive plot according to fertilization plan.

                                        Determined germination rate of seed planted in each plot.

 

6/26/2013                        Fertilized beans in competitive plot according to fertilization plan.

                                        Replaced defective moisture sensor in control plot.

 

7/2/2013                          Fertilized corn in AGGRAND plot.

 

7/3/2013                          Cultivated and weeded competitive plots.

 

7/9/2013                          Fertilized beans and corn in competitive plot according to fertilization plan.

 

7/11/2013                        Thinned corn to 20 plants each row; beans to 22 plants each row.

 

7/16/2013                        Fertilized AGGRAND corn.

 

7/22/2013                        Bean plants starting to flower.

 

7/23/2013                        Fertilized AGGRAND beans; fertilized corn and beans in competitive plot; watered all plants in control plot.

 

7/25/2013                       Determined plant vigor by measuring relative chlorophyll readings in all plots.

 

7/26/2013                       AGGRAND plot corn tasseling.

 

7/29/2013                      Fertilized AGGRAND corn; corn tasseling in all plots.

 

8/5/2013                        Noted many beans in all plots greater than 3 inches in length. Commenced harvest.

                                      Corn cobs forming in AGGRAND plot, with one cob silking.

 

8/6/2013                        Fertilized beans and corn in competitive plot according to fertilization plan.

                                      Continued to harvest green beans in all plots.

                                      Corn in control and competitive plots not silking.

 

8/8/2013                        Harvested beans in all plots; corn silking in competitive plot.

 

8/9/2013                        Watered corn in all plots; AGGRAND moisture sensor in corn plot read 54; corn silking in control plot.

 

8/12/2013                      Harvested beans in all plots.

 

8/13/2013                      Watered corn in all plots. AGGRAND moisture sensor in corn plot read approximately 70.

                                      Applied water in   each side of every row for a total of five, two-minute applications.

 

8/14/2013                      Harvested beans in all plots.

 

8/16/2013                      Harvested beans in all plots.

 

8/19/2013                      Harvested beans in all plots.

 

8/21/2013                      Harvested beans in all plots.

 

8/23/2013                      Harvested beans in all plots; watered corn in all plots.

 

8/26/2013                      Harvested beans in all plots.

 

8/29/2013                      Completed bean harvest in all plots.

 

9/4/2013                        Harvested corn in competitive plots.

 

9/13/2013                     Obtained soil samples at nine evenly spaced points in all plots.

 

9/16/2013                     Commenced tilling growth plots.

 

10/10/2013                   Performed soil respiration testing.

Table 3 Figure 14 summarizes fertilizer applications and mix ratios for each plot; 12,000 mL of fertilizer mix or water was applied with a watering can per row on all plants after initial planting and fertilizer application. The application date is shown in red. Control applications, containing only water, followed the same timing and volume as the competitor plot. Generally, the competitive fertilizer was applied at two-week intervals after sowing.

Table 3

Fertilizer Applications

fertilizing at planting, soil application, foliar feeding

Figure 14

AGGRAND fertilizer preparation and application

preparing to fertilize green beans, fertilizing green beans and corn
watering and fetilizing, liquid fertilizer application

As described in Table 1, the planting beds were sowed with a large number of seed and then thinned to provide the same number of plants in the AGGRAND, control and competitve beds. Plant thinning allowed for unrestricted development of the plants. On July 11, each green-bean plant row was thinned to 22 plants. Corn was thinned to 20 plants per row. (See Figures 15 and 16)

Figure 15

Thinning beans

properly thinning beans for commercial production

Figure 16

Growth plots after thinning

sweet corrn growth plots, backyard sweet corn

Post-Harvest

Harvest was complete on Sept.13, and soil samples were obtained in all of the planters. Soil samples, 4

inches deep, from nine evenly spaced points were obtained, mixed and forwarded to Midwest Laboratories.

Analysis included 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. (See sampling plan, Figure 17)

Three post-harvest samples were tested and all soil samples are summarized in Graphs 9-13.

Figure 17

Post-harvest plan and sampling

On Sept. 16, the growth plots were tilled, and the soil temperature and moisture probes were reset.

(Figure 18).

Figure 18

Plot Maintenance – Autumn 2013

garden tilling, plot maintenance

Plant Vigor

A Spectrum Laboratories Field Scout CM1000 Chlorophyll Meter (Plainfield, IL, Part # 2950, and Serial # 539) was used to acquire plant vigor data. The CM1000 is based on technology developed by NASA in the 1990s. The device provides a relative number that correlates to the amount of chlorophyll in the plant’s leaves. (NASA, 2011) Chlorophyll levels are an indicator of the amount of nitrogen in the plants and directly relates to the plant’s vigor. It also measures the nitrogen needed for optimal growth in instances of plant stress. (Murdock, et.al. 2004) This technology, developed by Spectrum as a handheld device, is effective in monitoring the growth of cotton, corn, wheat, turf grasses and many other crops. (Carson, 2004) Data variability comes from a number of factors such as chlorophyll levels, leaf texture and the amount of pubescence of the plant species.

 

On July 25, both crops were measured for relative chlorophyll levels. The readings were taken in full sun, between the hours of 10 a.m. and 2 p.m. for optimal intensity. See Figure 19. Chlorophyll levels are reported for both crops in Graphs 1 and 2.

Figure 19

CM1000 obtaining data with red absorbing and reflected beam

green beans, laser measurement

RESULTS AND DISCUSSION

 

Green Beans

 

Green beans are an easy-to-grow, high-yield vegetable that is popular with home gardeners. The germination

rate of the green bean seeds was very good, with 89 percent of the seed geminating in the AGGRAND plot,

85 percent in the competitive plot and 84 percent in the control plot. As reported earlier, an excess quantity of

seed was sown to ensure an equal number of plants were grown in each plot after thinning.

 

On July 25, plant vigor was determined by measuring relative chlorophyll readings of the leaves of a number

of green bean plants. Ten plants were selected at random. Data is summarized in Graph 1.

Graph 1

The data in Graph 1 shows that the AGGRAND plants had more chlorophyll than the plants fertilized with the competitive product, which means more nitrogen in the leaves for increased vigor. This is consistent with previous observations that plants subjected to the AGGRAND fertilization program yielded larger plants and developed earlier when compared to other fertilizers. This comparison was verified by the images in Figure 20.

Figure 20

Growth Progress - July 25

natural and organic fertilied green beans

AGGRAND

Control

Competitive

On Aug. 5, a number of plants held green beans that were more than 3 inches in length and harvest commenced. The AGGRAND plants revealed superior development and darker green color when compared to the plants in the competitive and control plots. Beans were picked and placed in plastic bags at each row. They were counted and weighed using an AND FX3000i digital balance, serial #: 15610355. See Figure 21.

Figure 21

Harvesting AGGRAND green beans - Aug. 5

harvesting green beans
green bean picking and harvesting

The green-bean harvest spanned several weeks, which included the following the harvest days: Aug. 5, 8, 12, 14, 16, 19, 21, 23, 26. Table 10 summarizes the green-bean harvest for 2013.

Table 10

Green-bean harvest – 88 plants per plot

charting green bean data

The AGGRAND fertilization system green-bean plot produced more and heavier beans per plant than the produce grown with the competitive fertilizer. As expected, the control plants fared the worst as far as quantity, total weight and average vegetable weight.

 

Sweet Corn

Growing sweet corn in Superior, Wis. can be a challenge because of potential cold early- and late- season temperatures caused in part by the winds off of Lake Superior. A short-season variety was chosen to provide full cobs in a relatively short growing season. Yields were surprisingly good despite the colder-than-normal temperatures in May and June.

 

Seed germination rates were very good with the AGGRAND plot at 88 percent, the competitive plot at 89 percent and the control plot at 93 percent of the seed producing plants. Seed was planted in excess with the goal of thinning each row to 20 plants.

 

On July 25, plant vigor was determined by measuring relative chlorophyll readings of the leaves of a number of corn plants. Ten plants were selected at random and results are summarized in Graph 2.

Graph 2

On Sept. 4, the AGGRAND corn was inspected for full maturity and harvested. Maximum maturity and resultant yield was not realized in the control and competitive plots. When picked, each cob was placed in a designated box and shucked in the AGGRAND laboratory prior to trimming and weighing. Each cob was trimmed even with the largest diameter end close to the kernels, counted and weighed using an AND FX3000i digital balance, serial #: 15610355. See Figures 22 and 23.

Figure 22

Corn Harvest -September

harvesting sweet corn

Figure 23

AGGRAND Fertilized Corn

sweeter sweet corn, bigger, delicious

The AGGRAND fertilization system produced more and heavier cobs of corn with fuller kernel development than the crop fertilized with the competitive fertilizer. A number of AGGRAND corn plants produced two cobs per plant. The control yield and size was lower than the AGGRAND and competitive plots. Table 11 summarizes the yields for the corn plots.

Table 11

Corn harvest - 80 plants per plot

Yield Summary

Table 12: Total Yield (by number) 2013 harvest

total yield by number (piece) 2013

Table 13: Total Yield (by weight, lbs.) 2013 harvest

Weather Observations

Historical weather data for the period 1909 to 2010 was acquired from Dr. Edward J. Hopkins, Assistant Wisconsin State Climatologist for observations in Superior, Wis. at position 46.70°N, 92.02°W, approximately 4.25 miles (6.84 km) southeast of the AGGRAND growth plots located at 46.73°N, 92.11°W. Temperature and precipitation comparisons covered a period from May through September where these parameters have the most influence on plant growth.

 

During the months of May, June and July 2013 average maximum temperatures were lower than the 100-year average, which resulted in soil preparation and planting about two weeks later than normal. Average maximum temperatures for August and September were higher than the 100-year average, enabling the crops to develop and reach maturity in a timely manner. Again, average minimum temperatures were lower than the long-term average for the months of May and June, but were above average for July, August and September. The overall average temperatures during the period from May through September were only slightly higher than the 100-year average. See Graphs 3, 4 and 5.

Graph 3

Graph 4

Graph 5

average temperature may - september, duluth minnesota

Precipitation during the 2013 growing season was variable. May and June received slightly above normal amounts, but August and September were below normal amounts. The overall lack of moisture when compared to the 100-year average and previous years required the garden plots to be irrigated on a routine basis.

Graph 6

Graph 7

total precip may - september

Soil Analysis and Respiration

Soil respiration is an indicator of microbial activity and soil health. This parameter is measured in the spring and fall to determine if one fertilizing regime was more effective in obtaining a response from the soil microbial community. Table 14 and Graph 8 summarize the respiration of soil samples collected during the spring and fall of 2013. As the data reveals, the respiration in the AGGRAND plot is greater than the Control and Competitive plots, and also varies, depending on the season. The soil samples collected in the autumn had a longer period of reduced moisture, thus reducing the microbial activity within the samples.

Table 14

carbon dioxide levels

Graph 8

CO2 respiration

At the beginning and end of every growing season, soil analyses are conducted to determine the relative health of the soil, the impact of the crops growing on the plot and to determine if the fertilizing programs are maintaining or enhancing nutrient levels. As with any cropping system, there is removal of vegetation in the form of fruit, roots and stems. After harvest, the corn vegetative materials were removed from the plot while the bean plants were distributed and tilled into the plots.

 

Comparing the initial soil samples taken during April 2010 and the latest samples from September 2013, nitrate nitrogen is the only nutrient that appreciably increased during the 2012 growing season but fell to levels similar to previous years during the 2013 season. This could be attributed to the microbial processing and subsequent uptake of the composted manure (AMSOIL, 2012).

 

Sulfur levels and iron increased in all plots. Copper, boron, sodium and manganese levels are comparable in all plots. Phosphorus, potassium, magnesium, zinc and nitrate levels are higher in the AGGRAND plot than in the control and competitive plots.

See Graphs 9 - 13.

Graph 9

Graph 10

Graph 12

Graph 13

CONCLUSIONS

The 2013 Growth Plot Study revealed that the AGGRAND fertilization program had increased vegetable yield in terms of number and total weight when compared to a leading organic fertilizer and the control plot. The average weight and size of the AGGRAND vegetables also showed an advantage over the produce grown in the control and competitor plots.

 

The competitive product evaluated in this year’s study is a liquid hydrolyzed fish-blend that is stabilized with phosphoric acid. This product readily mixes with water and is easily applied. Application rates are recommended every-other week during the growing season. The AGGRAND system enhances the soil environment and provides necessary nutrients, but requires the grower to monitor plant growth, flower bloom and fruit development for timely fertilizer applications. Timely fertilizer and soil amendment applications are important when the plant is expending more energy to develop flowers and fruit.

 

Nitrogen, phosphorus and potassium ratios (N, P, K) of the fertilizers employed in this study are 4-3-3, 0-12-0 and 0-0-8 for the AGGRAND program; and 3-3-0.3 for the competitive fertilizer. Both fertilizer systems tout products that are natural or organic and influence the soil in similar ways. The competitive organic product recommended a dilution rate significantly lower than the AGGRAND products, which is visually apparent when the products are mixed with water. The competitor produces a translucent liquid, while the AGGRAND product yields an opaque mixture. Mix ratios for the competitive product were obtained from the manufacturer’s product label or website and applied at the highest recommended rate to determine the performance comparison with the AGGRAND system.

 

The 2013 growth season started slow because of several snowstorms in April, plus cold temperatures throughout the month of May. Nevertheless, germination of all plants was favorable with almost no pest problems throughout the growing season. The above normal temperatures in August helped bring plants to full maturity in a timely manner, with harvest being slightly behind schedule. Residual nutrients in the AGGRAND plot coupled with the feeding during the growing season produced overwhelming yields. The AGGRAND system produced, by weight, 21 percent more beans and 29 percent more corn than the competitive system. The control plot, with no nutrient inputs, performed the poorest.

 

The AGGRAND plot continues to show overall better nutrient levels than the competitive plot with higher phosphorus, potassium and magnesium. In 2012, nitrate/nitrogen increased in all plots as a result of adding the same amount of composted manure. However, the AGGRAND plot tested higher for the nutrient, indicating the mineralization process via microbial activity is higher in this soil. This is supported by higher CO2 respiration values for this plot. The AGGRAND plot continues to show an increase in phosphorus levels and has reached the ideal level for vegetable growing. Soil samples will continue to be taken to monitor elements in the growth plots.

References

 

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AMSOIL INC. (2012). 2011 Vegetable Productivity Study. G-2957. Superior, WI: AMSOIL, INC.

 

AMSOIL INC. (2010). AGGRAND Soil Fertility Guide. G2792. Superior, WI: AMSOIL, INC.

 

AMSOIL INC. (2013). The Gardening Guide. G-1292. Superior, WI: AMSOIL, INC.

 

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National Oceanographic Atmospheric Administration. (2013). NOAA-supported scientists find large Gulf dead zone, but smaller than predicted. Available at: www.noaanews.noaa.gov/stories2013/2013029_deadzone.html

 

National Stone Association. (1986). Aglime fact book. Washington, D.C.: National Stone Association.

 

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