M Sc

The study entitled “Crop residue recycling for organic production of fodder
maize in a rice based integrated farming system” was undertaken during 2018-2020, at
College of Agriculture,Vellayani, Thiruvananthapuram, Kerala, with the objectives to
generate nutrient rich manures from rice straw through co-composting and to evaluate
their efficacy in influencing the growth, yield, quality and economics of fodder maize.
The research work was carried out as two experiments at the Integrated
Farming System Research Station (IFSRS), Karamana. Co-composting of rice straw
was studied in Experiment I, wherein rice straw was mixed with organic manures
including cow dung (T 1 ), goat manure (T 2 ) and poultry manure (T 3 ) the ratio 4:1 on
volume basis. In treatments T 4 , T 5 , T 6 and T 7, a ratio of 4:1:1 was followed. These
treatments were rice straw + cow dung + goat manure (T 4 ), rice straw+ cow dung +
poultry manure (T 5 ), rice straw + goat manure + poultry manure (T 6 ) and rice straw+
cow dung + glyricidia leaves (T 7 ). Natural composting of rice straw was followed in
T 8 with no addition of organic manures.
The time taken for maturation of composts, percentage recovery of composts
and quality parameters of different composts were found to vary significantly with
different co-composting methods. Rice straw co-composted with goat manure and
poultry manure in the ratio 4:1:1 (T 6 ) recorded significant earliness in maturity (74.33
days) and recovery (55.33 %) of compost. Treatment T 6 registered a narrower C: N
ratio (10.23:1) and was comparable to treatments T 4 (10.67) and T 5 (10.69). Compost
generated from T 6 recorded higher N (3.30 %) and P (0.90 %) content and was
comparable to T 4 and T 5. Higher K (3.22 %) content, was also noticed with T 6,
comparable to treatment T 7 (3.00 %). Micronutrient content was higher for treatments
T 6 , T 4 and T 5 .
Different rice straw composts generated from Experiment I were used for
organic production of fodder maize var. African Tall grown in summer rice fallows.
The field experiment was conducted from March to May, 2020 and was laid out in
Randomized Block Design with eight treatments and three replications. FYM @ 10 t
ha -1 was applied uniformly for all treatments as basal dose at the time of ploughing.The recommended dose of nutrients for fodder maize is 120: 60: 40 kg ha -1 . As
per soil test data, the NPK dose required for the experimental field was 85.2: 15: 37.6
kg ha -1 . In treatments T 1 to T 7 , respective composts prepared under Experiment I were
supplied on nitrogen equivalent basis to substitute for the recommended dose of
inorganic N and this was sufficient in providing the recommended P and K nutrients
also. For treatment T 8 (control), KAU Package of Practices Recommendation was
followed on soil test data basis. The results revealed that different treatments had
significant influence on the growth, yield, physiological as well as quality parameters
of fodder maize. Basal dose of 10 t ha -1 of FYM followed by chemical fertilizers (T 8 )
recorded taller plants at all stages of crop growth but was comparable to treatments T 6,
T 4 and T 5 . These treatments could also record higher and comparable leaf number per
plant as well as higher dry matter production at 40 DAS and at harvest stages of crop.
Physiological parameters like leaf area index, crop growth rate, relative growth rate
and chlorophyll content were observed to vary significantly under different
treatments. Treatment T 8 recorded higher green fodder yield (33.56 t ha -1 ) and crude
protein content (8.26%) and was comparable to organic nutrition treatments T 6, T 4 and
T 5 .
Soil nutrient status of the cropped field in terms of available nitrogen,
phosphorus and potassium was found to be better maintained than initial status after
crop harvest, in all treatments. Available P and K content were higher for organic
nutrition treatments T 6 and T 4, whereas available N remained unaffected by treatments .
Different treatments could not significantly influence the final soil pH and organic
carbon status of soil. Uptake of major plant nutrients was significantly higher for
treatments T 8 and T 6 . Treatment T 8 was identified as most remunerative in terms of
higher net returns (Rs. 39814 ha -1 ) and benefit: cost ratio (1.31). This was followed by
T 6, registering net returns of Rs. 27661 ha -1 and B: C ratio 1.20.
The present study revealed that co-composting of rice straw using nutrient rich
organic inputs could generate quality composts. When utilized for organic crop
nutrition of fodder maize African Tall, compost could result in comparable growth
and yield as that with the integrated nutrient management package recommended by
KAU. The study confirms that, rice straw which is lacking in quality for use as cattlefeed due to improper drying and which is often accumulated as a bio waste in fields
could efficiently be recycled for crop production and the technology is quite
promising for rice based integrated farmers for efficient recycling of farm resources.