TY  - BOOK
AU  - Anjali S
AU  - B Sudha (Guide)
TI  - Bio recycling for nutrient management and yield enhancement of rice (Oryza sativa L.)
U1  - 630 
PY  - 2023///
CY  - Vellayani
PB  - Department of Agronomy, College of Agriculture
KW  - Agronomy
N1  - MSc
N2  - The research work entitled “Bio recycling for nutrient management and yield 
enhancement of rice (Oryza sativa L.)” was conducted at College of Agriculture, 
Vellayani during 2020-2022 with the objective to identify a suitable crop nutrition 
package integrating bio resources and inorganic fertilizers for yield enhancement in 
rice.
The study was carried out as two experiments at the Integrated Farming System 
Research Station (IFSRS), Karamana. The first experiment included production of 
composts using different organic substrates viz., rice chaff, water hyacinth, salvinia and 
wild taro found associated with rice-based cropping systems. The experiment was 
carried out from September to December, 2021. The statistical design followed was 
Completely Randomized Design (CRD) with eight treatments and three replications.
From treatments T1 to T4, different substrates (rice chaff, water hyacinth, salvinia and 
wild taro) were co-composted using cow dung and poultry manure in the ratio 4:1:1 
(v/v). The substrates were co-composted using cow dung and goat manure in T5 to T8. 
The time taken for compost maturation, percentage recovery of composts and 
quality parameters of different composts were found to vary significantly with different 
co-composting methods. Co-composting of wild taro with cow dung and goat manure 
(T8) recorded significant earliness in maturity of compost (64 days) and was comparable 
to T6 (water hyacinth + cow dung + goat manure). Rice chaff co-composted with cow 
dung and poultry manure (T1) recorded highest recovery of compost (29.85%). 
Treatment T8 recorded a narrow C:N ratio (12.33) and was comparable to T6 (12.58).
The different composts varied in their nutrient contents also. Compost generated from 
T6 recorded higher N (2.28 %), P (1.08 %) and K (2.7 %) contents. T2 (co-composting 
water hyacinth with cow dung and poultry manure) recorded significantly higher micro 
nutrient contents and was comparable to T6. Co-composting of salvinia with cow dung 
and goat manure (T8) recorded the highest boron content. The content of silicon was 
significantly higher in T5 (rice chaff + cow dung + goat manure) and was comparable 
to T6. Content of plant nutrients was the lowest in T5. 
 
Different composts generated from Experiment I were used for crop nutrition of 
rice var. Uma. The field experiment was conducted from last week of January to first 
week of June, 2022 and was laid out in Randomized Block Design with 9 treatments 
and three replications. Following the recommended dose of nutrients (90:45:45 
kg ha-1
) for rice and based on soil test data, the NPK dose decided for the experimental 
field was 70.2: 16.6: 42.3 kg ha-1
. For treatment T1 (control), the KAU Package of 
Practices Recommendation for crop nutrition was followed on soil test data basis. From 
treatments T2 to T9, respective composts generated under Experiment I were provided
as basal dose @ 2.5 t ha-1
. This was followed by 75 per cent of the recommended 
nutrients as chemical fertilizers and 25 per cent through respective composts, on N 
equivalent basis. Full phosphorus was given as basal; whereas N and K were provided 
in equal splits as basal and at PI stage.
The results revealed that treatments had significant influence on the growth, 
yield and physiological parameters of rice. Basal application of compost 6 @ 2.5 t ha-1
followed by 25 per cent of the recommended nutrients through compost and the rest 
through chemical fertilizers (T7) recorded taller plants at PI and harvest, tiller count at 
all the growth stages and dry matter production at harvest. Physiological parameters 
like leaf area index and SPAD Chlorophyll Meter Reading were also the highest with
T7. Application of different composts significantly influenced the weed dry weight at 
20 and 40 DAT and significantly lower weed dry weights were recorded with T6. Grain 
yield (2933 kg ha-1
) as well as yield attributes were significantly higher with T7.
Soil nutrient status after crop harvest was significantly influenced by different 
treatments. The P and K status of soil was significantly higher in T7 (35 and 
167 kg ha-1
) and was comparable to T1. Different treatments could not significantly 
influence the soil pH, EC, soil organic carbon and available nitrogen after the 
experiment. Nutrient uptake by crop was significantly higher in T7 and remained
comparable with T8 and T1. Regarding economics, T7 recorded the highest net income 
(₹ 67, 476 ha-1
) and B:C ratio (1.59). This was followed by T1 with net returns 
₹ 55, 837 ha-1
and B:C ratio 1.58.
The present study revealed that bio resources like aquatic weeds and rice chaff 
associated with rice-based system could be value added through co-composting using 
 
locally available organic manures to generate quality composts. Application of water 
hyacinth compost (water hyacinth + cow dung + goat manure in 4:1:1 ratio v/v) @ 
2.5 t ha-1
as basal dose followed by 75 per cent of RDN as inorganic and 25 per cent as 
water hyacinth compost on N equivalent basis could be recommended as a prospective 
bio recycling option for higher yield and economics of rice during the summer season.

ER  -