Tips for management of tea garden soils
Know from a tea planter’s perspective
In plantations whether new or existing, tea plants are supposed to be a perennial crop. It lasts for at least fifty years. In many of the tea plantations in Assam, there exist tea areas that are over a hundred years’ old. Therefore, management of tea garden soils in the right manner is of utmost importance. The following points on soil management are mostly based on experience. These may be helpful for the small tea growers (STGs) in particular. In view of establishment of big gardens or major expansion of existing gardens are out of question in present scenario, the increasing number of small growers are going to assume a more important role in coming days. They now have become a major part of the tea community in Assam including other parts of the world.
Management of tea garden soils for new tea plantation:
Soil is heterogeneous. This means the characteristics, particle size etc. of soils taken from various locations in the same area may differ quite extensively. Therefore, soil of the areas proposed for tea plantation, irrespective of new or re-plantation, must be analyzed in a competent laboratory (TTRI in Assam’s case) prior to planting tea. For this, first you have to collect the soil samples from the site. Then it should be sent to laboratory in right manner.
Correct steps in taking soil samples:
- Divide the area into 1 acre block. If the area is 2 Hectares, make five blocks of one acre each.
- Take random samples from minimum of 20 numbers of boring.
- Samples should weigh around 500 gm each.
- They should represent the top and bottom soils separately.
- Take top soil is from top 6 inches of the boring.
- The bottom soil should be from the bottom 6 to 12 inches of the same boring.
- Thus we would get 20 top and 20 bottom soil samples from each block.
- Now mix all top soil samples thoroughly and make one single sample of 500 gm. This will represent top soil of the block.
- Same process should be followed for the bottom samples too.
- This way we will get one top and one bottom soil sample representing one acre block. The sketch roughly shows the boring done randomly in one block.
- Soil samples can be taken with a carpenter’s augur or an ordinary “khurpi” used for weeding, digging work. Samples should be taken in the same manner from all the other blocks. They should contain one top and one bottom soil sample of 500 gm each. For example, if there are 4 blocks, there will be 4 top and 4 bottom samples.
- Finally, all top samples should be thoroughly mixed.
- Then one common top sample of 500 gm, representative of all the four blocks is prepared. Only this master sample should be sent for analysis.
- Similarly, bottom soil sample of 500 gm should be prepared in same manner.
Final step – packing of the sample:
- The two samples prepared in the above way should be securely packed in clean polyethylene sleeves.
- They should be tagged as top and bottom soil sample respectively. The tags should be written clearly.
- These packets are finally packed in a sturdy cardboard box, destined to be sent to the concerned laboratory. For this the Tea Research Associations are the most preferred ones.
- Ensure that the sender’s address are clearly written.
- The box also should contain a letter from the sender as to explain why the analysis was required. It may be for extension planting or new plantation.
Basic parameters that are a must for a tea plantation
Determination of the following parameters of soil constituents are done during soil analysis:
- Acidity (pH),
- Organic matter (organic carbon)
- Available potash
- Available sulphur status.
- A brief history of the area viz. under scrub jungle/forest, a general over view of the soil topography, if possible, along with the soil samples could help in extracting a more comprehensive and accurate advice cum analysis report from the TRA.
Depending upon the age of the tea area, soil management of standing tea crop requires close attention. Following guide line should help the planters to monitor and manage soil in tea areas.
- Method of soil sampling is same as explained above. Thus, soil should be analyzed every third year in mature tea (4th year & above).
- Best time to draw soil sample is mid-December to mid-February. Gap between soil sampling and fertilizer application must be more than two months. Normally, fertilizer application is completed by mid-October. Dolomite could be applied after drawing soil sample.
- Soil sample should be drawn from between two normally grown row of tea in the section. Minimum twenty borings in one acre as explained above must be done.
- Close supervision is most important as planning/calculation all inputs to sustain good health of the tea would solely depend upon correctness of soil analysis.
- Following parameters are a must in analysis report.
- Soil Potash status (ppm potash).
- Soil pᴴ.
- Organic carbon content.
- It is advisable to get soil analysis done in TRA laboratory. It is possible to get their advisory service on the remedial measures if case these parameters are out of line.
Soil for filling polyethylene sleeves for tea nursery:
Only top soil sample (top 6″) is required to be sent for analysis. The soil analysis report must contain the followings.
- Soil pᴴ.
- Type of soil (with advice on ratio of coarse sand and soil mix if necessary).
- Organic carbon content (too rich soil initiate over callusing).
- Eel worm content (must in case of seed nursery).
It is strongly advised that soil for filling sleeves for tea nursery be analyzed at soil testing laboratory to get proper advice on conditioning of the soil prior to filling sleeves.
Article Contributed by Partha Sarathi Dowerah