Effect of Organic Manures and Fertilizers on Soil Organic carbon and Productivity of Groundnut in Loamy Sand Soil

Field: Agricultural and Biological Sciences (Life Sciences)

Groundnut (Arachis hypogaea L.) is the
premier oil seed crop of country. In India, 80 per cent
of the total produce is used for oil extraction, 11 % as
seed, 8% as direct food and only 1% produce is
exported. India contributes about 20% area and less
than 10% of oil seed production of world. Whereas, it
accounts 40% of the area (5.95 million ha
-1
) and 30%
of the production (7.54 million tonnes) of total oil
seed grown in India. In Rajasthan, groundnut covers
an area of 3.30 lakh hectares with 3.50 lakh tonnes of
production with an average productivity of 1087 kg
ha
-1
. Vermicompost is a prime source of organic
recycling of organic wastes and a good source of
macro and micro nutrients in chelated form and
fulfills the balanced nutrient requirement of plants at
longer period. Besides this, it also helps in
maintaining soil fertility and practices of precious
eco-friendly environment of the soil. Vermicompost
also helps in reducing C:N ratio and in increasing
humus content of the soil and provide a wide range of
nutrient in the readily available form to the plants,
such as nitrate, soluble phosphorus, exchangeable
potassium, calcium, magnesium (Singh and Tilak,
2006). Poultry manure is an important source of
nutrient and lays direct effect on plant growth.
Besides major nutrients, poultry manure also contains
traces of micronutrients which are generally not
supplied by the commercial fertilizer but essential for
plant growth. Use of biofertilizers can have a greater
importance in increasing availability of fertilizers
nutrients, fertilizer use efficiency and microbial
biomass. Hence, the study was conducted using
groundnut as test crop.
A field experiment was conducted during
kharif 2006 at farmer’s field, Ghatolia (Kalakh),
Jobner is located at 26.05
0
North latitude, 75.28
0
East
longitude and 427 meters above mean sea level in
Jaipur (Rajasthan). The soil was loamy sand, having
pH 8.1, 1.3g kg
-1
organic carbon, 130.6 kg ha
-1
available nitrogen, and 20.5 kg ha
-1
phosphorus and
149.5 kg ha
-1
potassium. The experiment consisted of
14 treatments, viz T0,
control-RDF of NPK (25 kg N+
50 kg P2O5 + 40 kg K2O ha
-1
); T1,
vermicompost 2.5
t ha
-1
; T2,
Poultry manure 2.5 t ha
-1
; T3,
Vermicompost
1.25 t ha
-1
+ poultry manure 1.25 t ha
-1
; T4,

vermicompost 2.5 t ha
-1
+ Rhizobium; T5,

vermicompost 2.5 t ha
-1
+ Rhizobium + VAM; T6,
vermicompost 2.5 t ha
-1
+ Rhizobium + VAM + PSB;
T7,
poultry manure 2.5 t ha
-1
+ Rhizobium; T8, poultry
manure 2.5 t ha
-1
+ Rhizobium + VAM; T9,
poultry
manure 2.5 t ha
-1
+ Rhizobium + VAM + PSB; T10,

vermicompost 1.25 t ha
-1
+ poultry manure 1.25 t ha
-1

+ Rhizobium; T11,
vermicompost 1.25 t ha
-1
+ poultry
manure 1.25 t ha
-1
+ Rhizobium + VAM; T12,

vermicompost 1.25 t ha
-1
+ poultry manure 1.25 t ha
-1

+ Rhizobium + VAM + PSB and T13,
25:50:40 kg
NPK ha
-1
+ Rhizobium + VAM + PSB. These
treatments were applied in randomized block design
and with three replications. Groundnut (var. M-13)
crop was sown on 13 June and harvested on 20
October, 2006. The application of half dose of N, full
doses of P and K and organic manure as per
treatments were applied at the time of sowing and
remaining half N was top-dressed at the time of first
irrigation. The sources of nutrients were taken as
urea, diammonium phosphate and muriate of potash,
respectively, for N, P and K. Seed was inoculated
with Rhizobium, PSB and VAM culture as per
treatment before sowing using standard method and
dried in shade. Intercultural operations were carried
out as per requirement of crop. Yield attributes and
yields were recorded at harvest. Soil samples
collected after harvest of groundnut crop were
analysed by adopting standard procedure (Jackson,
1973). The use of vermicompost, poultry manure in
combination with multi strains of biofertilizers
(Rhizobium, VAM and PSB), all treatments having
vermicompost, poultry manure with biofertilizers and
RDF NPK along with biofertilizers i.e. Rhizobium,
VAM and PSB brought about a significant increase in
the number of pegs per plant over either RDF or
vermicompost, poultry manure and vermicompost
along with poultry manure alone. However, the
highest number of pegs per plant (50.18) and 22.7%
pods per plant were observed under the treatment T13
(RDF NPK + Rhizobium + VAM + PSB) over rest of
the treatment combinations. Jain and Trivedi (2005)
reported similar results. The maximum number of effective and non-effective nodules