Agroforestry - Paulownia cultivation in Poland is a promising direction.
Agroforestry. Excellent agriculture.
Agroforestry and Paulownia cultivation in Poland is a land management system that combines crop and/or livestock production with trees and shrubs on the same land. The resulting biological interdependencies offer numerous benefits, including diversification of income sources, increased organic production, improved water quality, and enhanced habitats for humans and wildlife.
BENEFITS:
- significant climate improvement,
- 20% temperature reduction in tree shade,
- complete improvement of previously eroded and depleted soils,
- humus formation in sandy and depleted soils,
- Diversification of income sources in agricultural production,
- Rapid regeneration of large areas of degraded and desiccated soil,
- 190% increase in organic production,
- development of moisture and a humid microclimate,
- improved ecology, habitat for humans and wildlife,
- improved biodiversity,
- water retention and utilization,
- increased rainfall.
ALLEY CROPPING
Alley cropping is the cultivation of crops (grains, forage, herbs, vegetables, berries, etc.) between trees planted in rows. This means that everything normally grown in a field is cultivated between rows of trees: grains, grass, vegetables, berries.
For crop cultivation, this approach is called "woodland"; for forage cultivation, it is called "woodland pasture".
The space between rows is organized to accommodate mature trees while leaving room for alley crops. If light-loving plants like grains or grasses are planted in the alleys, the alleyways should be wide enough to allow light access even with mature trees.
Unexpected facts about agricultural efficiency
Another solution is to plan a change in crop rotation and harvesting as tree growth limits light access. For example, soybeans or grains can be grown when trees are very small; as the tree canopy approaches, forage can be harvested for hay; when trees are mature and the area is shadier, alleys can be used for grazing animals or shade-tolerant crops.
As with all complex systems, alley cropping requires careful and skilled planning. Crops and trees have requirements that sometimes necessitate intercropping between them. The design must provide sufficient space for the machinery needed to maintain each activity.
In most alley cropping systems, trees are planted in straight rows, sometimes disregarding terrain inclination and topography.
Paulownia trees are planted in strictly oriented rows, along the meridians in the Northern Hemisphere to minimize shading, and perpendicularly closer to the equator to obtain more shade.
However, planting Paulownia trees in an arc or along the contour has its advantages. These include slowing surface water movement and reducing soil erosion. Trees can be planted in single rows or in blocks of several rows between pathways. The first row of the block is planted on the contour line; subsequent rows are planted below the initial line depending on the terrain's slope. The last row of the block is planted parallel to the contour where the next block of trees will begin. The width of the tree blocks can vary, but the boundaries of the alleys where crops are grown are parallel. This arrangement avoids the formation of nodal rows in the alleys, which facilitates the maneuvering of agricultural machinery. The width of the corridors depends on the size of the machinery.
If contour planting is not feasible, an alternative is to plant trees in a zigzag pattern to intercept or at least slow down runoff water from slopes. Tree islands will offer some of the same benefits, as long as they do not interfere with agricultural activities.
In some areas, fast-growing deciduous trees or pines (auxiliary species) are planted as markers to ensure that trees from the main harvest develop straight, unbranched trunks. Alternatively, trees intended for harvest are planted in denser rows and then thinned and pruned as they grow. Although these early harvested trees have low market value, their presence in the early years of growth increases the value of the main crop. The goal is to produce long, straight logs with few lower branches to maximize profit from the final harvest. Regardless of how the plantation is designed, trees on the outer edges of groups will develop more lateral branches or even a twisted trunk, resulting in lower log value.
Thinning and pruning trees, as well as trimming branches and lower levels of canopies, enhances the soil fertilization process, strengthens the symbiotic relationship of trees with bacteria and fungi, and increases nutrient production. Pruned trees have greater photosynthetic efficiency than unpruned trees. Faster photosynthesis means more carbon and sunlight are consumed, which lowers the ambient temperature. A cooler environment means more water.
Calculations have also shown that nitrogen and other compound leakage is reduced by 50% compared to a plot without trees. Furthermore, tree roots intercept nutrients unused by field crops, which would otherwise be leached into groundwater. The nutrients intercepted by the trees then return to the soil as mulch.
Fallen deciduous leaves promote the development of fungi (their symbiosis with the plant root system - mycorrhizae), which significantly accelerates the growth of agricultural plants. Proper tree selection eliminates competition for moisture (mainly choosing species with tap or plate roots). Forest sunlight is somewhat lower than open fields, but other beneficial factors, as well as direct benefits from trees (honey, nuts, etc.), increase plot yields by up to 190% and add diversification in case one component fails to yield.
The presence of trees increases the number of bird species that are effective at killing pests.
Three species of linden (small-leaved, large-leaved, and Manchurian) and field maple can also be used as trees. These powerful honey-bearing plants yield up to 1000 kg of honey per hectare in continuous plantings.
FORESTRY
Combinations of trees and pastures are called agroforestry. Deciduous trees (sometimes walnut) and/or pines are planted in single or multiple rows, and animals graze among them.
The forest protects animals from wind and the soil from erosion, fertilizes and improves it. In addition, animals can hide in the shade on hot days, which they cannot do when grazing in fields. Trees also reduce the number of biting flies, which are very bothersome to animals (biting flies are visual and dislike shade).
WINDBREAKS OR PROTECTIVE STRIPS
Trees are planted in single or multiple rows along the edge of a field to reduce the impact of wind on crops or livestock. Windbreaks have been shown to reduce wind forces horizontally, corresponding to at least ten times the height of the trees. Wind and water erosion are reduced, while creating a more humid microclimate beneficial for crops. In winter, windbreaks trap snow, and winter crops or livestock are protected from icy winds. Beneficial insects in windbreaks find a permanent habitat, which increases crop protection.
Although trees compete for available water along the boundary between windbreaks and crop rows, potentially reducing yields next to the windbreak, the net effect on productivity is positive. In fact, even in areas well-prepared for high-quality crops, windbreaks can increase the yield of the entire field upwind by 20%, even if the windbreaks are included in the total crop area.
Windbreaks can be designed specifically to provide shelter for livestock. Studies have shown economic benefits from protection against wind chill, which is a major stress experienced by livestock living outdoors in winter.
Windbreaks reduce feed costs, increase milk production, and improve calving success.
In addition to protecting Paulownia crops and livestock, windbreaks offer other benefits. They help wildlife, for example, by providing a long corridor along which animals can move safely.
Protective strips can be converted into additional income centers: hunting leases, selective logging, trade in firewood and special forest products are just some of the possibilities.
All types of trees, including Paulownia, can be used as windbreaks. However, deciduous trees, even in multiple rows, will lose their effectiveness when they lose their leaves. For year-round use, some selected species should be evergreen. Fast-growing trees should be included; non-competitive species with deep root systems are best planted along the edges. Regular deep hoeing along the edges will prevent roots from entering crop rows. If some trees are regularly cut, new ones can be planted in their place, thus organizing a long-term rotation of the windbreak.
RIPARIAN BUFFER STRIPS
Trees, grasses, and/or shrubs planted along streams or rivers are called riparian buffers or infiltration strips. These plantings are designed to delay the movement of soil, excess nutrients, and chemical pesticides from the land surface before they enter waterways. They also reinforce riverbanks. In arable land where tile drainage has been installed to improve drainage, polluted water can flow directly into streams. Wetlands, organized as buffers, can intercept and purify drainage water before it enters the waterway.
Forested areas along rivers serve other community needs, mainly by storing water and helping to prevent bank erosion, which reduces siltation downstream. These areas also protect and enhance the aquatic environment. Shade over water makes it cooler, which is a prerequisite for many desirable aquatic species. At the same time, buffer strips provide habitats for wild flora and fauna and can be used for the production of special forest products.
FOREST FARMING. HARVESTING SPECIAL FOREST PRODUCTS
When natural forest land is used for both timber production and ancillary agriculture, it becomes an agroforestry system.
In addition to producing logs and sawtimber, forest lands can generate income from many other products. In the future, commercial Paulownia forests offer many non-timber "special forest products" that provide cash flow without requiring a one-time harvest of old-growth trees.
- fruits, nuts, berries,
- honey and other bee products,
- mushrooms,
- herbs and medicinal plants,
- materials for making baskets or weaving chairs,
- pine needles, branches, cones,
- plant materials as dried or fresh decorations,
- aromatic substances,
- fence posts, firewood, smoking wood,
- ornamental or unusual forest materials, e.g.,
- dyeing substances,
- tree and shrub seeds, seedlings, and forest residues,
- charcoal.