TY  - BOOK
AU  - Sreelakshmi, P
AU  - Durga Devi, K M (Guide)
TI  - Utilisation of potassium rich crop residues for retention of potassium in lateritic soil 
U1  - 631.4 
PY  - 2021///
CY  - Vellanikkara
PB  - Department of Soil Science and Agricultural Chemistry, College of Agriculture 
KW  - Soil Science and Agricultural Chemistry
KW  - Potassium
KW  - Rice straw
KW  - Plantain compost
KW  - Incubation intervals
N1  - M Sc
N2  - Potassium is a versatile vital nutrient for regular plant and animal growth and 
development. It is regarded as a "quality nutrient" because of its multifunctional role in 
metabolism. Kaolinite clay minerals prevalent in lateritic soils of Kerala, have lower 
activity and prevent the retention of available forms of potassium. Potassic fertilisers 
are often overlooked in fertiliser schedules due to their high unsubsidized cost. There 
are some K rich organic sources that are ignored by the farmers and are left or burnt in 
the soil. The utilisation of organic K resources like rice straw and plantain compost 
made from banana wastes are regarded good alternatives for synthetic potassic 
fertilisers. The present investigation consisted of three experiments viz., (i) assessment 
of decomposition dynamics of rice straw and its K release, (ii) K adsorption study on 
rice straw and prepared plantain compost and (iii) an incubation study in lateritic soil 
with different sources of potassium.
The decomposition rate of rice straw has increased with the period of its incubation and 
it showed only a partial decomposition of 51.9 % at 90 days due to the presence of more 
amount of lignin, cellulose and hemicellulose content which takes more time for its 
degradation. The potassium release rate increased to 84.28 % at 90 days of its 
decomposition.
The adsorption study on rice straw with different levels of KCl solution at different 
periods of decomposition revealed that as the solution concentration increased, the 
quantity of K adsorbed on rice straw also increased along with the increase in incubation 
period. Similarly, plantain compost that was prepared using vermi technology also 
showed an increased trend in the value of quantity of K adsorbed on compost as the 
KCl concentration increased. Because of its smaller particle size and larger surface area, 
plantain compost has stronger adsorption and buffer power than rice straw.
Rice straw with potash (T1), plantain compost with potash (T2), wood ash, FYM with 
potash (T3), rice straw with lime and potash (T4), plantain compost with lime and 
potash (T5), wood ash, FYM with lime and potash (T6), lime and potash (T7), potash 
alone (T8), and absolute control (T9) treatments were used in the incubation study. The 
physico-chemical characteristics of soil such as pH, EC, organic carbon, available N, 
P, Ca, Mg, S, Fe, Cu, Zn, and Mn were determined at initial and final days of incubation.
Data on the different fractions of soil K indicated that the treatment containing rice 
straw with lime and Muriate of potash (T4) showed the higher value of total K, 
exchangeable K and non-exchangeable K after 90 days of incubation. The reason might 
be that the presence of more inter planar sites in rice straw has trapped the K+
ions in 
fixed form since the material is not completely decomposed. At the same time 
incorporation of rice straw has enhanced the CEC of the soil thus enhancing greater 
adsorption of exchangeable K from unavailable forms by mass effect.
The current study showed that combining organic K resources with lime and K 
fertilisers resulted in significant increases in soil K fractions. Integrated application of 
rice straw with lime and K fertiliser can be considered as the best method for long-term 
cultivation because it has the ability to retain and release more K, particularly nonexchangeable, exchangeable, and total K, allowing for continuous uptake of K by the 
crops for normal growth and development. The usage of plantain compost in 
combination with lime and Muriate of potash has resulted in increased availability of K 
as well as micronutrients by maintaining favourable pH
UR  - https://krishikosh.egranth.ac.in/handle/1/5810186322
ER  -