Page 670 - e-Book

phosphorus by the soil organisms. It has been reported that C:N ratio was affected by soil

properties such as moisture content, texture, pH (Anderson and Domsch, 1980; Campbell et
al., 1991) and the C:N ratio is often used to describe the structure and the state of the

microbial community (Kaushik et al., 2006). The gradual decrease of soil moisture with
depth was due to the root system of the plant as the rootlets and roots were spread in the soil

just below the surface level and hold the soil water. Mature plants contained numerous root
nodules and caused by the native rhizobia already present into the soil.

The study indicates that the root nodule forming rhizobacteria may help to metabolize the

growth promoting phytohormone i. e. IAA by IAA-metabolizing enzymes within the plant
tissues. Formation of root nodules and production of IAA have much beneficial effects as the

nodule tissues are the good sources of this phytohormones. Metabolism of this phytohormone

within the plant tissues might have another importance as the edaphic factors of the
rhizospheric area were changes which results the increase of soil nutrients for the plant

growth. So hopefully the study will help to increase the knowledge of crop rotation and
cultivation of crops without or lesser use of chemical fertilizers in agriculture.

Plant 1 Mature root nodules Immature root nodules Total
Plant-1 32 10 42

Plant-2 33 09 42

Plant-3 27 09 36
Plant-4 38 11 49

Plant-5 37 12 49

Plant-6 35 13 48
Plant-7 28 11 39

Plant-8 36 12 48
Plant-9 30 10 40

Plant-10 34 13 47
Total 330 110 440

Average 33 11 44

Table 1: Total number of Root nodules (mature and immature) found in the plant Vigna radiata (L.) R.
Wilczek.
1 Age of all plants- 60 days
Size of plants- 14-18 inches
Time of year data taken-July

Whether manure given or not- not given
Flowering came or not- before flowering

660