Dear Kumari,

You research question may influence the features to be noticed in field. I am studying soil microorganisms, so in fieldwork I am always noticing the temperature of soil and air, moisture of soil and air, key plants on the research site (usually I will take the photo). Those are features to be different.

Of course, the coordinates and elevation - it should be quite stable.

Talking about the lab work, I will usually check the moisture (once more, to be more precise) total C, N, O, K content, total organic C content, ammonia, phosphates, pH and Eh. Those features will change permanently. Also it will be nice to check particle size distribution - this one may also vary slightly.

Hope, it helps!

Dear Kumari,

You research question may influence the features to be noticed in field. I am studying soil microorganisms, so in fieldwork I am always noticing the temperature of soil and air, moisture of soil and air, key plants on the research site (usually I will take the photo). Those are features to be different.

Of course, the coordinates and elevation - it should be quite stable.

Talking about the lab work, I will usually check the moisture (once more, to be more precise) total C, N, O, K content, total organic C content, ammonia, phosphates, pH and Eh. Those features will change permanently. Also it will be nice to check particle size distribution - this one may also vary slightly.

Hope, it helps!

Thanks ma'am

In the seasonal samplings of soil some of the basic parameters like temperature and moisture will be changing for the soil. This parameter have significant impact on microbiological properties like microbial population and diversity, soil enzymes activities etc. The soil parameters which are depending on them, must have to be considered. Some of the parameters like texture, BD , etc. generally, this may not vary with the season, but it also depends upon the management practices. Based upon the management practices you should decide the parameters to be considered and it depends on your research objective also.

Thanks

Thank you sir.

Before I suggest anything I wish to know your  specialization. Because the protocol for  looking  the morphological properties of soils in the field . is different from Pedologists to Soil Scientists/Earth Scientists.

If the in situ physical properties of the soil, like residual humidity or bulk density is aimed in your research, you should have a balance and the leak-proof bags with you to stock imidiatlly the samples.

Thanks to all of you,for your kind suggestions,

Dear sir @ D.K.Pal,I am working on the physico-chemical parameter,microbial enzymatic properties of soil and different form of carbon found in soil.Please give your valuable suggestions related or unrelated to these topics,which is surely going to improve our knowledge.

Apart from first being clear about your research question, which determines what you measure (including environmental factors [temperature, moisture etc.] that bear on your measurements (as others have noted), there are important statistical considerations. Establishing a difference between treatments at a point in time is different from establishing changes between two times - so I strongly recommend you consult an experienced and respected statistician regarding sampling strategies.  They will want to know the magnitude of change you might expect over time. 

Also be aware that land management often follows a seasonal cycle - rainfall is followed by cultivation that is then followed by planting etc.  It may be more important to sample according to an event within this cycle than to sample on the same date.  For example, by sampling according to date you could end up sampling before monsoon rains and cultivation in one year, and after rains/cultivation in another.  This would confound the results.

Thanks sir,can you please elaborate this interesting point of "Statistical consideration" in perspective of sampling and the concept of -Difference between treatments at a point in time is different from establishing changes between two times.

Time-series analysis is a specialised area of statistics.  You really need to talk to a statistician if your research involves field observations with both spatial and temporal aspects.

An older approach to time-series questions would be to treat the data as a split-plot in time. But nowadays I think you can do better.

Keep in mind that you statistical test will be more powerful if the sampling sites can be 'paired' (ie you re-visit the same site - which is not always possible) rather than times 1 and 2 both being randomly sampled - again, discuss this with your statistician.

answer to your question regarding seasonal sampling of soil in the field depends on various factors as listed below

1. type and objective of study:- crop oriented, nutrient oriented, genetical aspects of soil studies, nutrient leaching studies or off soil-landscape studies for erosion-productivity

2. The critical moisture and temparature affects  surface sampling of soil in forest areas versus crop land  Versus barren land surfaces.

3.Design of sampling of soil where in seasonal studies has a major role to interpret data sets

4. soil survey in tropical areas - we collect samples in two seasons mostly of summer(March to May) and in winter (November to February)- for physical and chemical characterization and classification.

5. Sampling seasons has no meaning for hydric soils in river belts and off paddy growing areas.

6. Generally for crop studies linked with nutrient cycling- seasonal sampling is preffered and collected samples during critical stages.

like wise - looking into the local conditions , soil sampling done by soil scientists and design sampling .

There are several factors that influence soil sampling sucha as: soil properties variations (horizontal and vertical); presence of soil fauna (termites, ants), soil landscape position (top, top, hillside, down)

 From one season to another, there is a change in biogeochemical cycles soil. Thus, certain physical characteristics (water status), chemical (content: Organic Carbon, Nitrogen, Phosphorus, Sodium, Magnesium), biological (microorganisms, macroorganisms such as fauna, and flora) and biochemical (including enzymes involved in turnover of soil organic matter).

The stage of growth of plants growing in the soil may be an important influence on nutrient and microbial dynamics.