Agriculture Form 3 – CROP PRODUCTION

FOREST CROP PRODUCTION

MEANING OF FOREST:This is a continues stand of trees which may reach a height of about 50m with crown touching or inter minghing often interlaced with leaves.

The canopy may be thick consisting to several district layers.

FOREST CROP: This refers to the forest stand and produce derived from the tree stand (pods, fruits, timber, fuel, soil conservation, shelter, pulps etc)

MAJOR FOREST TYPES IN TANZANIA

ROLES AND POTENTIALS OF FOREST IN TANZANIA

Apart from the direct objective of obtaining forest products e.g. timber, fuel, wood, poles etc it has following objectives:

o   Protect water catchment areas.

o   Preventing erosion (soil conservation).

o   Giving shelter to agriculture.

o   Providing habitat to wild fauna.

o   Facilitate scientific research in disease curing.

o   Provide employment in forest based activities e. g bees keeping.

o   As a form of insurance.

o   Land tenure rights.

FOREST MANAGEMENT

Meaning: This refers to the practical application of the scientific techniques and economic principle of forestry aimed at substituting yield of products derived there in.

The sustained- use of forest is done so as

a)      Stratification of the basic needs of the people living within the forest. b) To harvest all products at sustainable level.

b)      To facilitate improvement of attachment regulation, nutrient, recycling and maintenance of biological diversity measures.

         Prohibiting excessive logging operations to avoid environmental degradation and to prevent un controlled fires.

         Preventing accelerating agriculture development on the perennials and within the forest themselves through land use planning.

         To prevent uncontrolled exploitation for fire weed, char cools and development of deforestation.

         Encouraging artificially grown fire wood sources for industries and urban domestic fire wood supplier.

LOCAL AND EXOTIC TREE SPECIES AND THEIR VALUE

SILVICULTURAL SYSTEM

Meaning:

Sulviculture: This is the art and science of established forests naturally or certicially.

ARTIFICIALLY REGENATION

This involves the following operations:

i. Choice of species of trees and shrubs

ii. Site selection

iii. Nursery preparation

iv. Nursery sowing and management

v. Transplanting

i. Choice of species of tree and shrubs

The following should be considered

         Ecological requirement of the species I.e. climate, altitude etc

         Use of which a tree is to be put e.g. timber, poles etc

                   ii. Site selection is based on – plant indicators e.g. natural species growing on the site

         Condition of adjoining agriculture crops.

         Soil potential

                  iii. Nursery preparation (seed tree qualities

a.       Choice of seeds-good health tree

o   good form i.e. straight stem

o   small branches in relation to stem size and vigorous growth

b.      Where to collect seeds

o   Collect from one area where all the tree of the species being collected are virgorous and healthy.

o   Avoid areas with serious attack of seed borers.

o   Collect from within the natural home or indigenous species for this is the best tree grows.

c.       When to collect seed: when ripe

d.      Method of seed collection

o   Sort and grade sees and retain only the biggest/largest one for use.

o   For tree that split open e.g. carsia, wattle etc collection of the fruits is done before they burst open so that seed extraction could be done easily.

e.      Seed storage

•        Seed of the species commonly planted in Tanzania should be sown within one year of collection to avoid loss of viability.

When storing the following should be observed

         Seeds must have dried before being stored.

         The store must be dry and well ventilated.

         All seeds must be labeled with than name of the species, batch number and date of collection.

         Carry out frequent inspection and remove those damaged.

         Maintain the seed register, giving all details of the seeds in store

f.        Seed testing: This is done before sowing.

o   100 large seeds are cut open:- good seeds contain vernels which fill up the seed cut.

o   bad seed (which have less viability) contents are brown and strunked.

OR Water test: floaters are bad while sinkers are ok/good. *% of viability is then done/ calculated.

g.       Pre- treatment of seeds: This is done so as

o   To break seed dormancy and ensure rapid generation.

o   To improve vegetative growth associated with nitrogen fixing bacteria through inoculation. NURSERIES

Types:

A.      Temporary nursery

Advantages

         Cheap because no houses, stores

         Disease isolation is easy.

         Can be sited close to the planting area.

         Easy and cheap carriage of plants to the area of planting.

Disadvantages

         New ground must be cleaned every one to two years -high risk

         Plants in the nursery may be destroyed by animals hence- has higher running costs.

B.      Permanent nursery

Advantages

         Frequent watering and soil tilling makes the plant healthy.

         Full protection can be provided for the seedling including a resident nursing man.

Disadvantages

         Require more expenses to make house, stores etc

         Carriage of plants to area of planting is expensive.

         Can’t be sitted as close to the planting area as temporary nursery.

         Land may get exhausted.

         Spread of disease.

Details of permanent Nursery

Should posses the following:-

o   A good and permanent supply of water.

o   A good and well drained soil.

o   A good or easily accessible for haulage of materials.

o   Slightly sloping ground sheltered from strong wind.

o   Staff house should be near to the nursery.

o   Avoid heavy clay soils, swampy valley bottom and exposed hill top.

o   Use good soil mixed with forest soil, manure or sand and gravel before filling the polythene tubes. Operations of the nursery site

o   Clear all the trees, roots and stones.

o   Clear all trees within 30m of the nursery boundary (to avoid roots feeding from outside trees)-Fill the soil 30cm deep ; Remove and destroy anthills.

o   Uprooting born tree/ roots/ weeds outside the nursery area to the reduce risk of fungi, harmful to seedlings.

Nursery shape, size and layout

o   Square/ rectangular is best because of easy layout.

o   Size depends:-Number of seedlings to be raised each year.

o   Species e.g. other take less room compared to others.

o   How the plants are grown i.e. make it easy to allow further expansion.

o   Place the nursery seedbeds and store in the centre.

o   Fences, hedges and wind breakers

o   Should be created to keep at cattle and wild animals by use of barbed wires, wire must etc

o   For wind breakers and pigeon peas ornaments can be plant

Fertilizer application: Depends on the availability and use

o   Forest soil

o   Animal manure

o   Clay added if the soil forest is too sandy

o   Peat or compost can be added to make the soil of good nature.

NB: All these can be mixed to get standard soil mixture (mms)

o   Artificial fertilizer used in mixtures e.g. Ammonium sulphates, super phosphate, potassium sulphate

o   Application is done 3months in advance.

Watering: before 8am and after 5:30.

Mulching: to preserve soil moisture and suppress weed growth. Shade: to protect seedlings from rain drops, wind and water crops. Planting: before planting is done, packing out of soil moisture is done so as

o   to give move room for seedling to develop

o   to facilitate seedling to efficient water absorption

o   to facilitate easy transplanting due to compactness of roots

Pruning: root pruning should be done frequently to ennglish-swahili/courage” target=”_blank”>courage fibrous root system as well as making lifting of seedling easier and faster establishment.

Raising Seedling in temporary Nursery

o   Seedbed size: 0.9 m by any convenient length.

o   Spacing: o.9 m between seedbeds 7.5cm below plants.

o   Making seedbeds: Use ropes and pegs to mark then till the soil and mix and make as level as possible.

o   Soil mixtures: Must be done textured (i.e. 50% seined forest soil and 50%sand)

o   Sowing: Water seed beds with perenox at 2-2.5/ litres of water to destroy any dumping of fungi 3- 4 days before solving.

Water the bed one day before solving.

o   Mix fine seeds with sand twice their bulk.

o   Spread seeds with dry sand to twice its depth.

o   Form the converging with a broad flat board.

o   Water lightly and water again later on the day.

Shade: Should be in place until even germination has been obtained and seedlings look well established (usually 7-10 days)

Watering: Must be done using can with fine rose, Water with perenox at weekly interval

Transplanting

a)      Site selection

         Protect against termites

         Carry out drainage work

         Clean the site

         Till the land

         Carry out water conservation

         Carry lining out or pegging i.e. operation of marking the position when each tree is to be transplanted

         Digging holes, heap top soil and sub soil separately and during refilling by starting the top soil On a very wet ground use mounds.

b)      Should be done on the main rain.

         Avoid twisting or bending root during planting.

         Leave fertilizer in each hole and ennglish-swahili/courage” target=”_blank”>courage health start of seedlings.

         Spacing depends on

o   Cost

o   Rate of growth

o   Shape of tree

o   Demands

WOOD PRESERVATION

This is a chemical treatment done to wood for protection against:

         fungi: copper sulphate, sodium dichromate and acetic pentaoxide are used.

         nsects: dry bull tin oxide and penta chlorephend are used.

         water: using tour and paints

Methods of application

         Painting or spraying making the wood surface water proof.

         Soaking or boiling logs of timber in a chemical.

         Sap replacement: Lessons heat un pregnation by vacuum or pressure function pumps e.g. Creosola proteils timber against fire, fungi, bacteria and repel insects when heated penetrates tissues of timber.

Characteristics of good preservative

         Must contain toxic substance that can kill bacteria, insects and fungi.

         The chemical; must have residues/ presistance on the surface or inside the wood to be preserved.

         The chemical must not be flammable and water soluble and cheap.

         The chemical must have high penetration power in wood and low toxicity to human and environment.

LUMBERING

This is a process of timber harvesting i.e. removal of mature stem from natural forest or plantation.

It involves: Tree falling, conservation of logs or poles, extraction of road side, transportation to industrial site.

Methods of harvesting timber

Consists of either excavating a pit on the ground or placing support to the logs across the pit OR Erection of trees making a slope of which the logs are rolled. Peg scrows; 5m long or more are used.

o   The timber produced is earned manually from the sowing site to the nearest road and stacked. Advantages

o   Forest flow disturbed by log extraction is reduced.

o   Road density and subsequent soil erosion risk can be decreased.

o   Disturbance of wild life by machine use is less. Disadvantages

o   Is a selection falling, canopy gaps are distant from one another increasing eventual tending costs

o   Control of harvesting is made difficult

o   Small diameter log material and crows tend to be left as waste

o   Poor dimensional sowing often includes high value exports.

o   Use of chain saw machines is difficult.

AGRO-FOREST

This is a collective term used to cover a variety of land uses including tree growing, posture and crop production on the piece of land for the purpose of increasing or improving the output of the soil.

It involves planting trees and shrubs as purposely done in association on with other farm enterprises.

o   Benefits derived: Is a remedy of deforestation (source of wood fuel)

•        Source of income.

•        Environmental benefits

•        Beautification.

•        Labour sowing (women)

CHOICE OF TREE SPECIES AND SHRUBS

As a general rule tree and shrubs suitable for Agro forest should have these habits:

                     i.            Fast growth: the farmer does not have to wait long to get the end product e.g. firewood,fruits, timber

                   ii.            Deep rooted: this ensures minimum competition of soil nutrients and moisture with crop plants as well as resisting drought.

                  iii.            Nitrogen fixing: some leguminous spp are capable of fixing nitrogen as well as their leaves are rich in protein which then can be a good source of animal feed (cut as folder)

                 iv.            Good in by product production: this includes timber, poles, honey, etc such trees should produce products without affecting crop plants.

FORM OF AGRO FOREST (AF)

Depends on farm size and type of crops, growth habits of crop, topography, climatic factors and land conservation measures

i. Intensive hedge row (inter cropping)

•        Rows of trees or shrubs are planted between crops rows e.g. cereals (calindra) can be planted.

•        Achieved by planting the shrubs after every third row of maize at a spacing of 60cmx70cm

•        Such trees are pigeon peas, sesban, dinicidia

ii. Wide row planting

•        This aims at wood and tree products such as poles, timber, planted at a spacing of 8-20cm between rows and 4m for both trees.

•        Such trees are: coconuts, mangoes, avovado.

•        Trees for wood and timber spp e.g Cadca spp African black wood (mpingo), sycomolis (mkuyu)Acucia spp (figi)

iii. Boarder planting

This is planting of trees and shrubs along farm border for

a)      Protecting the farm as fence

b)      Mark boundary

c)       Farm wind break

d)      Provide wood and timber for fuel, building and for sale.

Such trees are: Eucalyptus spp

o   Marmacia spp

o   Greenidelea robusta

o   Sracunda minesitalia

Other harvested tree planting: for fruits, for fuel and sale.