Risks and Challenges of Modern Farming

The following is an excerpt from the Local Grown Salads Oxyfertigation Growing System patent.

To address the requirements and risks “modern farming” techniques have been developed that fall into several broad categories a) selection of seeds, b) monoculture growing techniques, c) harvesting and packaging of the products. Each category has many details and innovations, but creates new risks and challenges.

Seed Selection

Selection of the seeds to use is based on many criteria, which include disease resistance, yield weight, appearance, time required for growing, how long the vegetable will last after harvest, taste and nutritional value. This priority order is normally driven by what is the most profitable. Taste and nutritional value need to be last due to the realities of being profitable. The introduction of Genetically Modified Organisms (GMO) is one very effective (and controversial) technique. A seed is considered modified when a gene is artificially introduced; a GMO seed is contrasted with a hybrid seed, the traditional way to create a new cultivar through cross breeding. Farming mechanization and post-harvest processing is more cost effective when all the plants are the same cultivar. This is referred to as monoculture growing. By contrast, our Growing System's ability to grow large volumes of vegetables locally enables the farmer to select for taste, nutritional value and still achieve the same or greater levels of profitability.

Monoculture Growing Techniques

Monoculture growing techniques is the farmer’s equivalent to the introduction of the assembly line, as it is much easier to have acres and acres of the same cultivar growing. Monoculture allows equipment to be standardized and the processes repeated over and over again on a massive scale ensuring significant cost savings. This leads to a loss of diversity of choice for any particular vegetable. The loss of diversity means that different flavors, textures, and colors are also lost. Our Growing Systems allow the mechanical advantages of monoculture without the loss of diversity.

One negative impact of monoculture growing is that natural insect prevention is not available. In a mixed vegetable garden, natural insect prevention happens. In natural insect prevention the insect that is attracted to a tomato plant will eat an insect attracted to the basil plant. The insect attracted to the basil plant will eat one that likes the cucumbers, and the cucumber eating insect will eat a tomato-loving insect. Furthermore, the scents from one plant repel an insect attracted to another plant. Hence, naturally occurring insect prevention exists in mixed gardens. Without this natural means of keeping out insects, Monoculture farming requires large amounts of insecticides to control insects. With the introduction of DDT in the 1940's, the world began to enjoy production levels possible without losses to insects. However, with the publication of “Silent Spring” in 1962, the use of DDT began a rapid decline, followed by its eventual banning in 1972 in the United States.

By the 1970's, the economy, consumers and food manufactures expected low cost vegetables. To achieve this, the focus moved to increasing yields per acre. A major loss in yields were to insects. Therefore, a rapid and continuous development of different types of pesticides has happened. While not necessarily proven as fact in every instance, pesticides are “felt” to be harmful to people and the environment. By law or regulation in many jurisdictions, pesticide usage must be stopped prior to harvesting with the amount of time plants are pesticide free depending on the particular pesticide, cultivar, and post-harvest handling of the pesticide. And new pesticides must become developed as insects become resistant to them. Our Growing Systems do not require the use of any pesticides when fully deployed.

Monoculture continually grows the same plant which depletes the soil of its nutrients, requiring heavy use of fertilizers. Specifically, the process is that each plant needs a specific nutrient and micro-nutrient in a different amount depending on its growth stage. Plants remove these nutrients and micro-nutrients from the ground. They are replaced through the use of fertilizers. Fertilizers are designed to be used in soil, and therefore, will generally damage a plant when touching the plant. Therefore, they need to be applied prior to any substantial growth of the plant. The amount of fertilizer used by the plant and fertilizer lost to the environment is very difficult to accurately measure.  Thus, the farmer typically over-fertilizes. The excess fertilization typically ends up in the water system and harms the ecosystem. One well other known effect of excess fertilizer is “algae bloom” which will occur in bodies of water that farms drain into. Further, fertilizers feed weeds, which require the use of herbicides to remove.  Like fertilizer, herbicides spread outside the targeted area and affect untargeted plants. There is some concern that insects such as bumblebees are adversely affected. An example of a commercial herbicide is Roundup. Like pesticides and fungicides, herbicides must be stopped prior to harvest to avoid human ingestion. Our Growing Systems enable the exact amount of fertilizer to be added at exactly the correct time without any limitation on the harvesting of the vegetable canopy as the fertilizer is not ever intended to touch any part of the vegetable canopy.

Further, if a particular disease or pest can affect one single plant, then it can possibly affect all the other plants, as they also will be vulnerable to their attack. An infected plant, in this scenario, will be surrounded by infected plants, which will lead to the destruction of the entire crop. Our Growing Systems isolate the group into smaller sections, Growing Plank, Growing Unit, and Growing Room. Each of isolation provides an additional level of protection against the spread of disease.

In a two-year study from 2011-2013, the Canadian Food Inspection Agency (CFIA) found 78.4% of non-organic samples contained pesticide residues, violating the allowable limits 4.7% of the time. Organic fresh fruits and vegetables tested across Canada in the past two years contained pesticide residue. 45.8% of samples tested positive for some trace of pesticide and 1.8% violated Canada’s maximum allowable limits for the presence of pesticides. (http://www.cbc.ca/news/canada/manitoba/pesticide-residue-found-on-nearly-half-of-organic-produce-1.2487712, retrieved Aug 26, 2015).  From the scope of the problem it was assumed the farmers were not intentionally violating the standards, but the physical constraints of the individual farm environment that caused the results. Our Growing System's design provides a physical barrier that will stop the accrual of pesticides or other harmful airborne matter.

Harvesting and Packaging of the Products

A field is directly seeded or planted with transplants. With transplants, seeds are put into trays and grow within a greenhouse. When the plants are large enough they are transferred to the field for planting. Large commercial facilities use transplanting as there are higher yields and more opportunity for automation. In colder climates, the plants may be started in a greenhouse prior to the temperature being suitable for growing.

A plant needs four elements to grow and each cultivar needs them in different quantities and different specific details. The four elements are: light, water, nutrition, and atmosphere. The planting techniques used by the farmer are designed to ensure plants receive these elements while ensuring that harvesting is cost-effective. The first factor considered is plant spacing, which essentially means the space separation of the plant from its neighbors. Plants are planted in a row; the space between rows provides space for equipment. Within a row, there are typically several plants across. The inter-row space is lost production space and, thus, the farmer needs to minimize that space to maximize yields. Within the row, space in four directions is considered to optimize light to all leaves of the plants, water to the roots, and accessing the plants at harvest. If plants are too close, rain water won’t reach the roots uniformly, bottom leaves of the plants will not receive light, and depending on the plant itself, the plant may not form properly. If the plants are separated too greatly, the yields per square foot are reduced. Our Growing System’s design optimizes the delivery of light, water, and nutrients to each plant thus providing the best possible growing environment.

Water delivery through rain or irrigation will be included in plant spacing consideration. Water is delivered through rain, enhanced with sprinklers or irrigation methods. Currently, world food production depends heavily on rain fed agriculture. Only 20% of the world’s farmland is irrigated, but that farmland produces 40% of the world’s food supply. (Howell, T. A. 2001. Enhancing water use efficiency in irrigated agriculture. Agron. J. 93, 281–289).  The highest yields obtained from irrigation are more than double the highest yields for rain-fed agriculture. An advanced method of irrigation delivering fertilizer with water is called fertigation. The fertilizer is injected into the water being delivered to the plants. Large irrigation systems use “tapes” which are long flat flexible hoses placed in the rows of vegetables. The tape has small holes that release fixed amount of water to each plant. The holes are spaced in standard positioning and typically a plant will be located at each hole. The capital cost of this form of irrigation system is large and there are many technical problems, the most common being that water is not delivered because the holes are blocked by insects, fertilizer, and other debris. Another difficulty is that once the system is in place, tilling of the soil and removing dead plants can damage the irrigation system. The holes will plug and water will not be released. Further, plants must be positioned correctly with respect to each hole.

Nutrition is delivered in the form of fertilizer. Typically, the soil is fertilized prior to the planting. Once the plants are growing, it is difficult to deliver the fertilizer, and the fertilizer can damage the plants. Our Growing System's watering system provides water directly to the root’s of the plant containing the exact amount of fertilizer (nutrients).

Harvesting methods are Continuous,One Time, or Cut-and-Come-Again.

In Continuous harvesting, the harvesting does not destroy the plant and is repeated on some cycle suitable for the plant. This method is used for strawberries, cucumbers, tomatoes and the like as the plant continuously flowers and produces vegetables or fruit for a complete cycle.

In One Time harvesting the crop is cut and the plant destroyed. Depending on the plant, the root might be harvested or handled post-harvest. Iceberg lettuce, carrots, and most other root vegetables are harvested this way.

Cut-and-Come-Again harvesting is traditionally used in backyard gardens or by small farmers. In this harvest method, the plant is cut above the crown. After some time, the plant regrows the vegetation that has been harvested. Almost all green vegetation plants (even celery) may be harvested this way. But the need for harvesting skills, long grow times, and short growing seasons make the method impractical for most commercial agriculture operations. “Cut-and-come-again” harvesting is an economically effective method of harvesting, as it enables the time and materials used to create a strong root structure to be reused multiple times by multiple harvests of the vegetable canopy. Our Growing System's design provides a growing environment that is economically viable to perform “cut-and-come-again” harvesting.

Harvesting of plants is either by hand or machine. When done by hand, its labor intensive, and by machine capital intensive. When choosing hand or machine harvesting, the selection is dependent on the cultivar, produce quality required, damage caused by harvesting, and plant spacing.

The time for harvesting is usually a short window before the winter season. In warmer locations, multiple harvests may be performed all year. Crop harvest must be performed at the optimum stage of maturity. Full red, vine-ripened tomatoes may be ideal to meet the needs of a roadside stand, but totally wrong if the fruit is destined for long distance shipment. Factors such as size, color, content of sugar, starch, acid, juice or oil, firmness, tenderness, heat unit accumulation, days from bloom, and specific gravity are used to schedule harvest. The result of harvesting at an inappropriate stage of development can be a reduction in quality and yield. Unfortunately, plants within a specific field will not be consistent due to factors like seeds, water distribution, and weather patterns, fertilizer distribution, to name a few items. While a target date can be estimated in well in advance, the actual date cannot be confirmed without regular and thorough measurements, which improve the accuracy as the date approaches. Once the harvest date is set, the weather can seriously impact the ability to actually perform the harvest. For example, a severe thunderstorm would stop a harvest due to danger to the harvesters, while a severe heat wave would damage the produce during the harvest. Our Growing Systems allow harvesting to be performed at the optimum time to maximize the qualities demanded by the consumer.

Once a harvesting date has been determined, the time of day and the weather affect the quality of the harvested produce. Plants have dew on them and release moisture at night. Vegetables are best harvested in the cool morning hours so that they stay crisp and store longer. If harvested too late in the day, they become limp and wilt quickly, having evaporated much of their moisture and absorbed the midday heat. This is especially important for leafy greens like lettuce, chard and fresh herbs such as parsley and basil. It also applies to crisp fruiting vegetables like peas, and anything in the cabbage family like broccoli and radishes.

It has been estimated that more than 40% of perishable commodities are lost after harvesting through post production since they are living, respiring tissues that start senescing immediately at harvest. Freshly harvested vegetables are mostly comprised of water, with most having 90 to 95% moisture content. Water loss after harvest is one of the most serious post-harvest conditions. Consequently, special effort is required to reduce the effects of these naturally-occurring processes if quality harvested in the field will be the same at the consumer level.

Special skills are required for proper harvesting, handling, grading and packaging of vegetables in order to ensure optimum produce quality at the marketplace. It makes little difference what the quality is at harvest if it is reduced by poor handling, packaging or storage conditions. Price received for produce is determined by quality at the marketplace, which occurs after harvesting.

Harvested vegetables remain fresh through respiration. Higher respiration rates indicate a more active metabolism and usually a faster deterioration rate and may result in more rapid loss of acids, sugars and other components that determine flavor quality and nutritive value. The increased oxygen demand due to the higher respiration rates of fresh-cut products dictates that packaging films maintain sufficient permeability to prevent fermentation and off-odors. The physical damage or wounding caused by harvesting increases respiration and ethylene production within minutes, with associated increases in rates of other biochemical reactions responsible for changes in color (including browning), flavor, texture, and nutritional quality (sugar, acid, vitamin content).

Rapid cooling as soon as possible after harvest is essential to the maintenance of optimum quality. The first consideration at harvest is removal of the produce from direct sunlight, and secondly, to pre-cool as quickly as possible. There are a number of pre-cooling methods available a) Room Cooling, b) Pressure Cooling, c) Hydro-cooling and d) Vacuum cooling.

Room Cooling is exposure of produce to cold air in an enclosed space. This is the simplest and most common cooling method. Cold air normally is discharged horizontally near the ceiling so as to enable it to return through produce stacked on the floor. Since cooling is slow, shipments may be delayed or in some cases the product may be shipped without adequate pre-cooling. Certain commodities, such as snap beans, may deteriorate before cooling is accomplished. These problems are minimized by ensuring that containers are stacked to facilitate good air circulation. Fans must be powerful enough to move the air at a velocity of 2 to 4 miles per hour among the containers, which should be vented adequately.

Pressure cooling is used for strawberries, fruit-type vegetables, tubers and cauliflower. It is accomplished through the use of fans and strategically-placed barriers so that cold air is forced to pass through the containers of produce. This method usually takes from 1/4th to 1/10th the time required to cool produce by passive room cooling, but takes two or three times longer than hydro or vacuum cooling.

Hydro-cooling is used for stems, leafy vegetables and some fruit-type vegetables. Hydro-cooling is one of the most efficient of all methods for pre-cooling. Produce is drenched with cold water, either on a moving conveyor or in a stationary setting. In some cases, commodities may be forced through a tank of cold water. Hydro-cooling is an excellent method for bulky items such as sweet corn, peaches, or cantaloupes. Good water sanitation practices must be observed and once cooled, the produce should be kept cold. The cold water must come in direct contact with the product, so it is essential the containers be designed and filled in such a way that the water does not simply channel through without making contact.

In vacuum cooling, commodities are enclosed in a sealed container from which air and water vapor are rapidly pumped out. As the air pressure is reduced, the boiling point of water is lowered so the product is cooled by surface water evaporation. Vacuum cooling works best with products that have a high surface to volume ratio, such as lettuce or leafy greens. The method is effective on produce that is already packaged providing there is a means for water vapor to escape. Moisture loss from the commodity is generally within the range of 1.5 to 5.0%. Generally, about 1% of the weight is lost for each 10o F the product is cooled. Our Growing Systems enable the temperature at the time of harvest, through packaging, to be completely controlled, thus reducing the complexity of handling and reducing the adverse effects on the product through the packaging process.

One of the major problems encountered during storage of certain vegetables is chilling injury. Another important consideration in order to maintain optimum storage conditions is relative humidity. Small fluctuations in temperature can cause wide fluctuations in relative humidity. Products stored at less than optimum relative humidity will suffer excessive water loss and begin to shrivel. Many vegetables are unacceptable for marketing if weight loss reaches 5% because of their undesirable appearance and undesirable textural changes that may accompany water loss. Leafy vegetables are among the less tolerant crops to dehydration.

Storage of different cultivars together may or may not be safe. There is a cross-transfer of odors and volatile compounds such as ethylene are emitted by some cultivars that may be harmful to others. Ethylene also stimulates ripening of many fruits and vegetables. This ripening effect is negligible at low temperatures (e.g., 32° F), but it may have an effect at higher temperatures. Traditional farmers use internal-combustion engines in and around farms and the engines release some ethylene in their exhaust. Several commercially-available materials either absorb ethylene directly or convert it to inactive compounds. Certain types of activated or brominated charcoal absorb ethylene; however, some cheaper materials utilize potassium permanganate to oxidize ethylene to simple carbon dioxide and water. Manipulation of the storage atmosphere, whether in large storerooms or in small packages, can reduce the detrimental effects of ethylene. In general, reducing oxygen and increasing carbon dioxide serves this purpose and is a commercially acceptable procedure for some products.

A key element of food safety of commercial vegetables is traceability. Traceability is the ability to verify the history, location, or application of a vegetable by means of documented recorded identification. Traceability implies that when a consumer in New York City gets sick from eating a salad purchased locally, it will be possible to trace the salad to the manufacturer, through the supply chain to arrive at a farmer in Idaho. The farmer may then check his/her records for the day when the romaine was harvested, to identify a worker, who skipped a standard procedure, and went from helping clean the pig pen to harvesting the romaine lettuce.  The need for traceability is strong on a farm where volumes are high and contaminants from animals, ground water, and the environment have easy access to the vegetables.

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