Benefits of Perennial versus Annual Crops

Plant life on Earth can be divided into two distinct categories – annuals and perennials. Annuals have a single-season lifespan, while perennials can live for several seasons, on up to multiple centuries. Similarly, farm crops can be categorized the same way – though we see multiple distinctions, aside from just lifespans, between both.

The Annual Dilemma

Annual-crop farming practices – raising those short-lived fruits, vegetables, and herbs, which comprise 70% of the world’s farming market – are today’s major contributors to an overall insecure global food supply, which is losing the capacity to feed a rapidly growing, hungry human population. While many industry experts are arguing for new annual crop-growing technologies and breeding programs to close the widening supply gap, still others blame the conventional, chemical-based methods of farming in general, as being the culprits sponsoring a game that cannot be won.

It may be pointed out that a shift to worldwide organic farming may be a way out of present annual-crop dilemmas, yet we see that presently, only 1% of commercial farmland on the planet is organically managed.

Annual crops demand a much higher resource allocation than do perennials overall, with yearly costs on the rise, of irrigation, fertilization, and various soil treatments, biocides, genetics and breeding, land tillage, and the need for crop rotations – all of which persistently push market food prices ever upward – a spiraling frustration to consumers worldwide. The global annual crop economics overall paint a lukewarm picture at best, on the demand side. This, despite annuals receiving government subsidies in most of the world’s developed countries.

Non-Organic Annuals & the Environment

Environmental damage and remediation resulting from conventional annual-crop farming is perhaps the darkest chapter in this story. Due to machine-friendly row farming techniques and the persistent use of various powdered soil additives and chemical sprays, depleted farm fields enter another spiral, that of the slower dog chasing an ever-shorter tail.

Large-scale row farming with chemical fertilization traditionally results in depleted topsoil, which is carried away by flowing irrigation water, which flows as polluted silt to local waterways, lakes, or seas. The results are poorer soil quality that needs yet higher injections of factory-contrived nutrients as well as chemically adaptive microbial and insects needing yet more combative prescriptions.

Before land even becomes a farm field, the requisite deforestation and land-clearing not only releases naturally sequestered carbon, but can result in a rise of the local water table. This tends to mobilize any salts in the subsoil region. Add to this, deposits of farming chemicals and we are looking at a recipe of ill health for economies, local humans, and nature.

Perennials in a Good Light

On the other side of the food aisle, perennial crops have been almost ignored on a global scale over the past century, despite holding great promise for the future of farming on many counts. Since the Neolithic days of early farming, the flora food supply was comprised of annuals and perennials grown together, a practice that largely continued until about 100 years ago. There are many explanations for the shift to a dominant focus on annual crops in the last century; as a result, the promise that perennials now hold for the future of world food is undeniable, and stands poised at peak impact potential.

Perennial Crop Energy and Nutrient Density

Mark Shepard is a permaculture instructor and owner of the New Forest Farm in Wisconsin, a 106-acre permaculture managed perennial farm in the heart of the North American Oak Savannah Biome. New Forest Farm attempts to mimic the indigenous perennial crops that are native to the region. According to Mr. Shepard, his perennial crop array outperforms corn (as an example) for energy density (calories-per-hectare) by approximately 30% and for nutrient density (vitamins and minerals, etc.) by a much larger percentage, while providing a balanced, healthful diet.

Maintaining Soil Health

Integrating a perennial farm with grazing animals (agroforestry) can also realize multiple benefits. Mr. Shepard explains that with the chickens, cows, and pigs roaming the farm grounds, crop fertilization and soil revitalization is not a problem, much of it occurring in-situ, with various manures often directly produced where they are needed. The remaining soil deficiencies have been mitigated by mineral amendments, which have been applied to the site only three times in the last 15 years.

Biofuel Production

Energy markets also stand to benefit greatly with more focus applied to perennial crop cultivation. Mr. Shepard points to the superiority of apples over corn as a bioethanol feedstock, as apples contain all of the essential ethanol processing ingredients (water, sugar, and yeast). This process’ self-containment bypasses much of the process that corn stock must undergo. This results in a much higher net energy gain realized in apple bioethanol than for corn.

Summary

The aforementioned present-day disadvantages of annual crops serve to highlight the numerous advantages of Growing & Supporting Perennial Crops

• Perennials tend to have deeper root structures – as deep as 60 meters – harvesting water in the subsoil long after it drops below the reach of annuals. This alone is a strong indicator of the innate intelligence of the agroforestry option – the planting of multi-storied crops together.

• Deeper roots mean higher soil stability; perennials are well suited to maintain soil structures on slopes and riverbeds.

• Mature trees – with the cooperation of mycelium – develop moisture nets around root structures, ensuring the survival of other local life forms through droughts and winter periods.

• Perennials tend toward a natural resilience, weathering natural catastrophes such as droughts, gale winds, and floods, better than annuals – providing a higher degree of asset security, and resulting in higher real estate values.

• Well-chosen perennials for their location tend to be higher in nutrient-use efficiency than annuals, requiring less nutrient, and requiring little or no soil tillage in between seasons. Less labor and lower soil enrichment expenses.

• Trees situated in high water tables will naturally transpire large amounts of water through canopy and leafage, thereby lowering the water table. Salt-resistant varieties will help mitigate dangerous salinity factors.

• Perennial crops can effectively compete in the marketplace despite having no subsidies; annual crops in more than 21 developed countries receive government subsidies.

• Perennial forage crop varieties may be planted as mulch and ground cover under tree crops, thereby mitigating weeds, regulating ground temperature, producing crops, and forage for grazing animals.

• Animals can harmonize well in perennial environments as opposed to annuals, so long as crops are out of reach or are not natural food sources; forages and weeds will feed the animals, activity and rooting will cultivate the soil, manure will enrich the soil.

• Perennials such as nuts and some fruits have long shelf lives, thus are suited for long-distance transport, and long-term or winter storage.

• Nut, seed, and berry perennials in particular, are well suited for high-value upmarket products such as preserves as well as butters, oils, dried goods, and energy foods.

• High-energy oils from certain perennial nuts are prime candidates for biofuels such as biodiesel, both in fuel quality and feasible per-hectare yields, offering viable alternatives to the destructive mass production of biofuel corn.

• Many perennials outperform most annual crops in energy and nutrient-density, even in metric-tons-per-hectare yield, while offering a higher degree of sustained, long-term production.

• In a multi-story or poly-cultural perennial design, the efficient use of vertical space – by stacking companion or compatible crops at successive levels up to canopy, allows for a bio-intensity not possible or feasible with annual crops. This also allows for the sequestering of carbon not found in the annual crop lineup, which is an important step towards the mitigation of climate change.

All told, a fully developed and mature perennial, poly-cultural farm performs at high nutrient-use efficiencies, regulates the water table, sequesters carbon, stabilizes and maintains soil structures, bolsters against extreme weather events, minimizes external inputs such as fertilizers, encourages biodiversity and beneficial insect habitat, and is overall a wise choice in developing a long-term food production culture worldwide.

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