No-Tillage Farming (1973)

Livres - Reiman Associates - Shirley Phillips et Henry Young Jr. (1973) - 228 pages - Arable crops

Arable crops No-till

No-Tillage Farming is a cropping technology that aims to achieve higher yields at lower costs while preserving the soil. It represents a significant departure from conventional tillage methods, which involve extensive turning, stirring, sifting, and combing of every acre of soil annually. This book, No-Tillage Farming, was published in 1973 by S. H. Phillips and H. M. Young, Jr., and aims to disseminate facts about no-tillage to farmers and agricultural technicians.

Détails sur le livre

• Éditeur : Reiman Associates
• Nombre de pages : 228 pages

Definition and Evolution

No-tillage farming is described as a system that approximates the methods used by indigenous peoples before the arrival of the Pilgrims in America, yet it is as new as chemical farming and aerial seeding. It is also known by other terms such as “zero-tillage,” “sod-planting,” “direct-planting,” “direct-seeding,” and “no-till”. The book traces the evolution of tillage, from crude wooden tools to the plow, then to excessive tillage with steel implements, followed by “minimum” tillage methods, and now to “no-tillage” through a combination of technologies. The conventional moldboard plow began losing favor in the 1950s to tools like the chisel plow and disk plow, with early experiments already exploring the elimination of all tillage.

Authors

• S. H. Phillips was the Assistant Director of Extension for Agriculture at the University of Kentucky. He had been active in no-tillage development since 1963, authored many articles, lectured extensively, and organized numerous demonstrations and seminars on the subject.
• H. M. Young, Jr. was a no-tillage farmer from Christian County, Kentucky, who began experimenting with no-tillage techniques on a small scale in 1962. His 1,235-acre farm attracted over 10,000 visitors interested in no-tillage crops, and he also contributed widely through papers, articles, and lectures.

Key Advantages of No-Tillage Farming:

1. Soil Conservation and Erosion Reduction: No-tillage significantly reduces wind and water erosion by leaving crop residues and dead sod on the surface, creating a protective mulch. This is particularly crucial in areas susceptible to dust bowls and in glacial or coastal plains soils. Studies showed soil loss from no-tillage corn watersheds to be dramatically lower than conventional tillage, even on slopes.
2. Soil Moisture Retention: Crop residues act as insulation, reducing evaporation and increasing water infiltration into the soil. This leads to more favorable soil moisture conditions for crops, especially during dry periods, and can carry a crop through a drought when conventionally tilled corn would suffer moisture stress.
3. Increased Land Use Potential: By reducing erosion risks, no-tillage makes it possible to use marginal or submarginal land, including steeply sloping land, for row crop production.
4. Reduced Machinery Investment and Power Requirements: No-tillage eliminates the need for plows, disks, and harrows, thus reducing the overall machinery investment and horsepower requirements for tractors. This makes it more accessible for small and part-time farmers.
5. Lower Production Costs: Cash operating costs for no-tillage systems are significantly lower than conventional or many minimum tillage systems, primarily due to reduced labor, fuel, maintenance, and depreciation costs associated with fewer field operations.
6. Improved Timeliness of Operations: No-tillage allows for more timely planting and harvesting, especially in wet springs or during double cropping, by eliminating time-consuming seedbed preparation. This helps avoid yield reductions from late planting.
7. Reduced Soil Compaction: With fewer trips across the field by heavy machinery, no-tillage greatly reduces soil compaction, eliminating plow pans and improving soil conditions.
8. Enhanced Root Development: Roots in no-tillage systems develop more compactly, often with greater lateral growth near the surface, as they find favorable conditions of fertility, moisture, temperature, and soil porosity. Corn roots, for instance, were found to be ten times more numerous in the top two inches of killed sod than in conventionally tilled soil.
9. Pollution Reduction: No-tillage effectively reduces air pollution from windblown dust and water pollution from soil and chemical runoff by preventing soil movement. Pesticide concentrations in runoff water and eroded solids are significantly reduced.
10. Double Cropping: No-tillage systems provide added economic impetus to double cropping by reducing weather risks and time required for seedbed preparation. This allows for increased production volume and better utilization of land.

Challenges and Considerations:

1. Weed Control: No-tillage relies heavily on herbicides, as mechanical weed control is difficult. Farmers must carefully select and apply suitable contact and residual herbicides, sometimes needing tank mixtures or dual applications. Special weed problems like witchgrass, crabgrass, nutgrass, volunteer corn, buckhorn plantain, smartweed, and Johnson grass require specific control strategies.
2. Soil Temperature: Mulch covers can keep no-tillage seedbeds cooler during the day, potentially slowing germination and early plant growth, especially in northern latitudes or poorly drained soils during early spring. However, nighttime temperatures are often warmer, and adapted crops can tolerate these changes.
3. Insect and Rodent Problems: Crop residues and sods can provide favorable conditions for some insects (e.g., armyworms, slugs, root aphids) and rodents, potentially increasing their populations. Closer observation and appropriate insecticides or baits are necessary.
4. Disease Incidence: While some diseases may decrease, certain crop diseases like yellow leaf blight in corn might be more difficult to control as causal organisms can overwinter in residues. Crop rotations can help manage this.
5. Planter Adjustment and Seed Coverage: Planting in various soil, moisture, and crop residue conditions requires proper planter adjustment, especially for depth control and ensuring firm soil contact around the seed.
6. Fertilization Adjustments: Broadcast surface applications, supplemented with banded row starter fertilizers, are common. Increased nitrogen rates (20-25% higher than conventional tillage) may be needed due to potential losses or stratification, although specific placement of phosphorus and potassium has been shown to be effective even with surface application. Lime also needs more frequent, but smaller, applications at shallower depths.
7. Appearance: To farmers accustomed to finely pulverized soil, the residue-covered surface of a no-tillage field, with only narrow planter row marks, may appear “unkempt” or “disquieting”. However, success does not depend on seedbed appearance.

Key Practices and Components:

• Herbicides: Indispensable for weed and grass control, replacing mechanical tillage. Contact herbicides (e.g., Paraquat) provide quick “burn-down” of existing vegetation, while residual herbicides suppress new growth.
• No-Tillage Planters: Specialized equipment, often featuring fluted, angled, or chisel coulters, is essential for cutting through residues, creating a narrow seedbed, placing seeds at proper depths, and ensuring good seed coverage.
• Residue Management: Leaving crop residues on the surface as a mulch is a cornerstone of no-tillage, providing soil protection, moisture retention, and organic matter.
• Crop Rotations and Double Cropping: These practices are highly compatible with no-tillage, offering economic advantages, improved weed and pest control, and intensified land use.
• Fertilization: Includes broadcast surface applications of nitrogen, phosphorus, and potassium, often supplemented with banded row starters. Anhydrous ammonia and liquid nitrogen sources can also be used with specific considerations.
• Sprayer Operation: Requires careful adjustment of boom height, gallonage, pressure, and nozzle size for thorough coverage, especially when dealing with dense vegetation. Accurate mixing of chemicals and understanding specific gravity effects are crucial.

Economics

No-tillage can lead to significant cost reductions compared to conventional tillage, primarily through decreased labor and machinery costs. Studies in Ohio and Kentucky showed that no-tillage could result in savings of $4.00 per acre compared to conventional tillage in selected costs. Yields from no-tillage are generally equal to or sometimes higher than conventional tillage, particularly in dry years due to improved soil moisture. The system also offers benefits like increased timeliness, which can lead to higher overall farm income and better utilization of farmer’s time.

Future Outlook

The authors anticipate continued developments, including earlier planting capabilities, new herbicides and varieties allowing for more intensive cropping (e.g., two corn crops per season), expansion of no-till to more crops (tobacco, vegetables), improved machinery, and new weed control methods focusing on plant exudates and selective pest management. The adoption of no-tillage is expected to increase globally, supported by implements adapted for both small and large farms.