This document discusses methods for evaluating soil fertility, including deficiency symptoms, tissue analysis, and biological tests. Tissue analysis involves extracting plant parts with reagents and comparing nutrient concentrations to standards. It is a quick way to monitor nutrient levels at different growth stages. Biological tests use microorganisms to quantify a soil's ability to supply nutrients and are simple and require little space. Together, these methods help identify limiting nutrients and inform fertilization practices to maintain optimal nutrient levels.

1. Ranjithveeran A
2019031056

2. Soil fertility evaluation:
It is the potential of the earth or inherent capacity of the
soil to supply plant nutrient in quantity forms and
proportion required for the growth and development of the
crop.
Fertility is measured by the amount of chemical elements
or compound required for plant growth.

3. Deficiency symptoms
Tissue analysis
Biological tests

4.  Careful inspection of growing seedling or plants can help
identify specific nutrient stress.
 If a plant is lacking in a particular nutrient, characteristic
symptoms may appear.
 Nutrient deficiency symptoms must be related to some
function of the nutrient in the plant.
 Visual symptoms may be caused by more than one nutrient.
 In a set of nutrient omission and addition pot experiments,
exact limiting nutrients can be identified.

6.  • The concentration of the nutrients in the cell sap is usually a
good indication of how well the plant is supplied at the time of
testing.
 These semi quantitative tests are intended mainly for verifying
or predicting deficiencies of N, P, K, S and several
micronutrients.
 Method: the plant parts may be chopped up and extracted with
reagents.
 The intensity of color developed is compared with standards
and used as a measure of nutrient concentration.
 Tissue tests are quick, easy to conduct and interpret

8.  For tissue tests, the time of sampling and plant part to
be sampled have already been standardized for many
crops.
 Tissue test can be done 5-6 times in a season and
concentration can be monitored in the farm premises.
 There can be two peak periods of nutrient demand,N
during maximum vegetative growth and second during
reproductive stage.
 Fertilization can be done to maintain the peak
concentration at critical stages.

9. Simpler and rapid laboratory/ green house techniques
utilize small quantity of soil to quantify nutrient
supplying power of a soil.
By using various cultures of microorganisms soil fertility
can be evaluated.
These methods are simple, rapid and need little space.
Winogradsky was one of the first to observe in the absence
of mineral elements certain microorganisms exhibited a
behavior similar to that of higher plants.

10. Title Soil Testing and Plant Analysis
Issue 3 of SSSA Book Series
Issue 3 of Soil Science Society of
America book series, ISSN 1047-
4986
Volume 3 of Soil Science Society of
America book series: Soil Science
Society of America
Editors Robert Lee Westerman, Soil Science
Society of America
Edition 3, revised
Publisher Soil Science Society of America,
1990
Original from the University of Michigan
Digitized 3 Mar 2010

11. http://ecoursesonline.iasri.res.in › viewSAC: Soil
fertility evaluation
Title Soil Fertility and Nutrient
Management
Editor Roma Doshi
Edition illustrated
Publisher Scitus Academics, 2016