Hortipastoral Systems for Orchard Floor Management in Fruit Orchards
Authors: Suheel Ahmad, Nazim Hamid Mir, Sheeraz Saleem Bhat and D K Verma
ICAR-Indian Grassland and Fodder Research Institute, Regional Research Station, K D Farm, CITH Campus, Rangreth, Srinagar-190007 (Jammu and Kashmir)-INDIA
The North Western Himalaya exhibit a great diversity in climate, landforms, ethnicity, resource availability and agricultural practices. The great mountain chain covers about 13% of geographical area in India and this vast hilly area provides ample opportunities for livestock rearing. But the production potential of Indian animals in general and those in Himalayan regions is way below the global averages (about 50-60% less). Among the many factors limiting the productivity of livestock, inadequate availability of quality feed is the most important one. High yielding and nutritious fodder is essential for scientific and economic management of livestock, especially cross bred. Livestock production is more efficient from cultivated fodder than from the degraded grazing lands but unfortunately the fodder cultivation has remained static and only 4% arable land in J&K is under fodder production. There is acute shortage of fodder especially green nutritious fodder, which is the major cause of low productivity of the livestock, especially in hilly area. In animal husbandry about 65-75% expenditure is incurred in feeds and fodder. The regional deficits are more important than the national deficit, especially for fodder, which is not economical to transport over long distances. The pattern of deficit varies in different parts of the country. For instance, the green fodder availability in Western Himalayan, Upper Gangetic Plains and Eastern Plateau and Hilly Zones is more than 60% of the actual requirement. In Trans Gangetic Plains, the feed availability is between40 and 60% of the requirement and in the remaining zones, the figure is below 40%. In case of dry fodder, availability is over 60% in the Eastern Himalayan, Middle Gangetic Plains, Upper Gangetic Plains, East Coast Plains and Hilly Zones. In Trans-Gangetic Plains, Eastern Plateau and Hills and Central Plateau and Hills, the availability is in the range of 40-60%, while in the remaining zones of the country the availability is below 40%. Due to ever-increasing population pressure of human beings, arable land is mainly used for food and cash crops, thus there is little chance of having good-quality arable land available for fodder production, unless milk production becomes remunerative to the farmer as compared to other crops. Hence to meet the current level of livestock production and its annual growth in population, the deficit in all components of fodder, dry crop residues and feed has to be met from either increasing productivity, utilizing untapped feed resources, increasing land area (not possible due to human pressure for food crops) or through imports.
HORTIPASTORAL SYSTEMS AND FORAGE PRODUCTION
Among the fruit tree based agro-forestry system, the hortipasture systems have been recognized as sustainable land use option because of its high productivity and environmental benefits even under fragile agro-ecosystem. Fruit tree based land use has been acceptable as a viable alternate land use system. Hortipastoral system is socially accepted, ecologicallyfeasible and economically viable for class IV and V types of lands, where fruit trees are grown in association with grass and legume.The integrated approach of growing fodder grasses and legumes under agro forestry and silvi- pasture systems is one of the vital alternatives to augment fodder production. Intercropping of perennial forage grasses and/or legumes with fruit crops is fruitful for high forage and fruit production. Horti-pastoral system (orchards+ pasture+ livestock) where in the inter spaces between fruit tree species are utilized for cultivation of grasses and grass legume mixtures. Due to increased population, poor productivity of grassland resource and deficit in forage supply and farmer’s inability to spare their cultivated land for forage production, it is essential to utilize the interspaces in these horticultural tree plantations. Having a slow growth initially or during formative years, the interspaces not only go without productive use but also become vulnerable to weeds causing trouble in the different orchard operations. Pasture component in the horticultural fruit crops has also reportedly been very promising intervention with respect to profitability and orchard floor management.
ORCHARD FLOOR MANAGEMENT
Orchard floor management is vital to tree health, yield, and fruit quality. Current standard management practices include maintaining a vegetation-free tree row and a grass- covered alleyway. This system is effective at limiting competition from undesirable vegetation and creating a favorable environment for the fruit trees. Orchard cultivation refers to the careful management of the orchard soil in such a way that the soil is maintained in a good condition suitable to the needs of the tree with least expenses. This involves maintenance of the physical condition of the soil, its moisture and nutrient content. Apple trees are relatively poor competi-tors with other vegetation because of their low root density per unit of soil, 1 to 10 cm root per cm3 compared with 103 cm per cm 3 for grasses. Therefore, high tree productivity depends on low weed competition A good system of orchard cultivation should ensure:
l. Weed control and saving in moisture and nutrients
2. Very little disturbance to soil and preventing soil erosion and
3. Reduced cost of cultivation
METHODS OF SOIL MANAGEMENT PRACTICES
This type of cultivation is extensively followed in India. This involves regular ploughing and removal of weeds. The clean culture has many disadvantages. They are:
i. Humus will be completely depleted rapidly due to frequent cultivation.
ii. Frequent cultivation causes injury to the feeding roots, the trees may be short lived or stunted in growth.
iii. Clean cultivation aids in more aeration leading to the depletion of nitrogen.
iv. Hard pan is created in the soil.
v. Frequent cultivation causes more soil erosion.
The above mentioned defects in clean cultivation can be minimized by avoiding deep and frequent cultivation and also cultivation when the soil is too wet.
Clean culture with cover crops
This type of soil management involves raising of a cover crop or green manure after removing the weeds. If clean cultivation is attempted during the rains, considerable erosion is almost sure to occur. It is probably best to plant a green manure crop between the trees early in the rains and plough it into the soil towards the end of monsoon season. In India, green manure crops like Sunhemp, Cowpea, Daincha, Lupins etc. are more commonly used. Legume cover cropping in grape, mango, guava and other fruit crops is becoming a common practice in the management of orchards. Cowpea and French beans grow well under apple trees. In some places to prevent soil erosion, certain permanent cover crops like red clover, white clover, alfalfa are raised in the alley spaces. They are leguminous crops, establish in a short period and fix atmospheric nitrogen and conserve soil moisture.
SWISS SANDWITCH SYSTEM
The ‘‘sandwich’’ system has been developed in Switzerland as a new method of living mulch combined with modified tillage. Annual or perennial crops are sown in a nar-row strip (40 to 50 cm wide) within the tree row, whereas the soil to each side of this strip is tilled. Weed control around the tree trunks can be avoided by having a low-growing vegetated strip and the narrow cultivated strip at each side of the tree row can provide a competition-free zone for tree roots. This method is reported to show the lowest costs for practical weed control without any negative effect on tree performance and yield. The sandwich system can also de-crease pests and diseases and increase bio-diversity, improve soil conditions, and enhance nutrient cycling. However, several challenges to sand-wich systems must be resolved such as choosing living mulch mixtures that have minimal competition, avoiding rodent problems, and adjusting vegetation growth with-out any negative effects on apple yield, fruit quality, and storability.
In this method, permanent cover of grass is raised in the orchard and no tillage is given. This may be useful in slopy lands for preventing soil erosion. But they compete for soil moisture and available nitrogen. The drawbacks of this system are the need for increased manuring and water application. They are harmful to shallow rooted trees. Hence sod may be useful with deep rooted trees because soil moisture will be very low on the top layers. The primary purposes of alleyway cover crops are to stabilize the soil to reduce erosion and minimize dust, support wheel traffic, minimize compaction, encourage predator arthropod populations and to suppress weeds.
This is similar to sod with the only difference is that the vegetation is cut frequently and the cut material is allowed to remain on the ground. This is slightly better than the previous one, as the moisture loss is not so great as in sod. In both sod and sod mulch, more nitrogen should be applied to the fruit trees than usual application because the vegetation utilises more soil nitrogen.
Commonly used grass species for orchard alleyways:
I. Creeping red fescue
II. Perennial rye grass
III. Tall fescue
IV. Orchard grass
The best management practice is to integrate these grasses with legumes such as redand white clover, sainfoin, alfalfa, berseem, cowpea, pea, winter vetch, crown vetch and soyabean. Legumes provide additional nitrogen in the orchard. Mowing and discharging the nitrogen rich plant material in the tree row effectively bands the nitrogen next to the tree roots. These act as living mulches and stabilize the soil against erosion and compaction, and reduce dust and mud.
Each of the alternative orchard floor management practices discussed has advantages and disadvantages. Environmental conditions and crop determine the orchard floor management systems that may be successful in a given location. Regardless of which system is used, attention must be given to the factors of weed suppression, soil stability, irrigation requirements and pest dynamics, to ensure a given orchard floor management system enhances yield of marketable fruit, tree health, and improves the orchard environment.
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