Agronomic and Cultural Practices

Proper land selection, adoption of appropriate soil conservation measures and improvement of soil fertility through rehabilitation ensures better plant establishment and early canopy formation which eventually provides an early ground cover.


Planting tea

Planting tea in contour using healthy and vigorous plants of recommended clones with appropriate plant populations for different clones would ensure better establishment and uniform growth, which could provide a better ground cover.

Bush formation (Bringing into bearing)

Bush formation or bringing into bearing operation, which begins, from the nursery is extremely important to obtain a good canopy structure. Centering by cutting of well established plant followed by tipping at correct stage is of paramount importance in proper bush formation. Plucking-in is not recommended as it results in poor canopy formation.

Bush management (Plucking)

A good ground cover could also be achieved by maintaining bush health and vigour of the plants through out the pruning cycle. This is possible only by adopting proper plucking policies, with respect to standard, frequency and severity, which not only helps to maintain a good ground cover but also enhance productivity.

Pruning

Adoption of correct pruning practices with appropriate pre and post pruning operations ensures uniform recovery from pruning and provides an early ground cover. The prunings should be allowed to remain in the field, which improves soil fertility, and also act as mulch.


Shade and green manure crop management

High Shade stand of Gravillea robusta


Establishment of green manure crops and shade trees at recommended spacing intercept the incident light and reduce the impact of rainfall drops. Further, leaf litter and lopping of shade trees at regular intervals provides substantial amount of biomass, which not only act as mulch but also increases organic matter content which enhance soil fertility. Therefore, shade plays a multiple role in the ground cover management in tea plantations.


Pests and disease management

Adequate measures should be taken to control and manage any pest or disease attack, which may affect the canopy and healthy growth of tea.

In-filling of vacancies

The vacancies or gaps that occur as a result of casualties from times to time gets gradually expand causing soil erosion and heavy weed infestation. Therefore vacancies should be planted with soil rehabilitation grass(Mana grass - Cymbopogon confertiflorus or Gautemala grass - Tripsacum laxum) or establish a ground cover such as Arachis pintoii until such time they are infilled with recommended clones. Infilling of vacancies should be done at every pruning and all the weak plants, which are mere passengers, should be culled and infilled.

Ground covers


Ground covers play an important role in sustaining and improving fertility status of soil. Beneficial effects of ground covers are conservation of soil and moisture, reduction in soil erosion, improvement in soil fertility and suppression in weed growth. In general, there are two different types of ground covers which are presently adopted in tea cultivation;

Thatching – Application of surface mulch
Live mulch - Cover crops and soft weeds


Thatching or mulching

Inter raws in young tea mulched with grass



The importance of thatching or mulching in young tea is well known. It is one of the main components in the package of integrated weed management. In order to realize the full benefit of thatching, it is necessary to maintain the thatch layer until tea canopy provide and adequate ground cover. Therefore, it is necessary that the layer of thatch is re-laid well before the material completely breakdown. However, in practice re-thatching is hardly adopted due to non-availability and non-sustainability of material. Approximately forty tons of material is required to thatch one ha and this amount could obtain from one ha in a single lopping of Mana grass, which is sufficient only for the first thatching at planting. For subsequent thatching, materials will be a problem unless there is a thatch bank available in the estate.

Cover crops

Cover crop Arachis pintoii




The cover crops can play an important role in sustainable agriculture as it improves the soil aggregation, increase infiltration capacity and hence decrease the risk of runoff. In addition, cover crops also suppress weed growth.




Intercropping

Tea and Rubber













Tea & Coconut








In any intercropping system, the objective is to utilize the available area fully using the resources of production. Under such situation, the land utilization is very high and hence there is a less opportunity for land to remain exposed. Therefore, intercropping systems of tea and rubber, tea and coconut provides an efficient ground cover management option.




Tea and Coconut + Pepper









Sloping Agricultural Land Technology (SALT)






SALT in tea steep tea land


SALT is a package technology on soil conservation and crop production. Investigations have shown that it could be used as an alternative measure for soil conservation and fertility management in tea lands. “Hedgerows” play a key role in SALT and these are lopped at regular intervals. The loppings can act as good surface mulch, which has a direct relevance to ground cover management. Therefore, in addition to other benefits, SALT also can play an important role in the ground cover management in sloping tea lands.

Land selection for tea cultivation

Prior to land selection it is important to consider the climatic requirements for tea cultivation such as 2500-3000 mm annual rain fall and 19-25^oC ambient temperature and most important soil requirement i.e. acidic soil of pH 4.5 – 5.5.

Why land selection is so important?

In order to ensure maximum return it is necessary to provide most conducive soil conditions for better establishment of plants and attain high yields. This is particularly important as cost of establishment of tea is so high. In addition, cultivars branded as high yielder demand best of soil conditions for it to perform well. These objectives are not realized if land selection is not done properly and all these efforts get wasted if we cannot get expected returns. This is only possible if optimum crop yields are realized. In order to achieve optimum yields it is imperative that most suitable land for tea cultivation is selected. This will no doubt result in good plant establishment that eventually cover the ground in double quick time protecting the soil well. This is vital as soil is rather exposed during plant establishment and it is considered as the most vulnerable period for soil erosion.

How to select a suitable land?

There are several criteria to consider in selecting a land for tea cultivation.

Slope

Slope of the land which has to be below 55 per cent however it has to be below 70 per cent % due to high vulnerability of soil for erosion in Mid Country.

Soil depth

Soil depth should be over 100 cm to support good root system.

Gravel & Boulders

Surface should not have more than 10% gravel and boulders

Soil profile

Soil profile or soil layer should not impregnated with more than 10% gravel

Next step or operation after land selection is land preparation. Land preparation involves clearance, adoption of soil conservation practices and soil rehabilitation prior to planting tea. In my next post I hope to go into these topics.

How can we maintain a good cover on soil?

In my previous post I have given an overview on soil protection.This post will help you to improve your knowledge on soil further...

There are so called recommended practices for growers to follow to protect soil, in the long run it would help them to enhance crop yields and also preserve environment. These are basically aimed at maintaining a good ground cover throughout the period. How can we have a good cover on soil? Let us see what are the ways and means of achieving this. Technically these are known as Agronomic and cultural practices. These are nothing but Good Agricultural Practices – so called GAP, one has to take care of in any form of farming or cultivation. First of all I would like to list them as follows;

Agronomic and Cultural Practices:

Land selection:
Contour planting of tea
Bush formation
Bush management (plucking & pruning)
Shade and green manure crop management
Weed management
Crop Protection
In-filling or supplying vacancies

I would like to elaborate all the practices listed above in my next post

Do you know that soil is the most valuable resource for tea cultivation

What do you know about soil? Well, soil is a mixture of particles derived from earths crust and humus or organic matter. Soil is vital to sustain very existence of plant life. Soil formation is such a so slow process that it takes about 1000 years to build 1 inch (30 cm) of soil. But, it can get lost in no time due to man’s activities such as cultivation of crops.

You know that soil anchor the plants and provide necessary nutrients for its existence. Therefore, to sustain crop yield it is necessary to protect and manage soil properly. For a crop like tea, situated mostly among sloping lands in Sri Lanka, caring and nurturing of this valuable resource is a must. Compare to other tea growing countries our productivity, Yield per hectare (YPH) is low. Why? I think we have lost most of the fertile top soil which got eroded over the years and deposited in reservoirs, lowering their capacities as well, consequences of which is a different issue no doubt link to poor soil protection.

In addition, there has been a widespread declining yield trend in most of the plantations. This is attributed to various factors like climate change, man management, crop management, recurrent droughts etc etc. but not on soil management until recently. Where lowering of soil fertility is the common topic for all the ills. It is no secret that to maintain soil fertility one has to protect soil.

With this introductory remarks, let’s see how we can protect our soil in tea plantations from from the beginning so to speak. To see how it is done, please await for my next post to be published in due course.