Enhancement of Nutritional Status of Vermicompost through Application of Different Organic Solutions during Composting
The present investigation was carried out at the faculty centre of Integrated Rural & Tribal Development and Management under the School of Agriculture and Rural Development of Ramakrishna Mission Vivekananda University, Morabadi, Ranchi-834008, Jharkhand, India at 23.230 N latitude and 85.230E longitude with the altitude of 2,140 feet above sea level during January-2011 to May-2011.
The experiment was conducted based on twelve different treatments such as T1 = 3 days old cow urine (5%); T2 = Beej Sanjiboni (20%) (9 days old); T3 = Beej Sanjiboni (10%) (9 days old); T4 = Sashayagavya (20%) (11 days old); T5 = Sashayagavya (10%) (11 days old); T6 = Rice boil water (density = 0.998 g/cc); T7 = Mustard oil cake soaked solution (5 days after soaking in water @ 1 kg/5 litres then dilute it with mixing one part mustard oil cake solution with five parts of water); T8 = Fly ash soaked solution (5 days after soaking in water @ 1 kg/5 litres then took decoction and diluted it with mixing double quantity of water); T9 = Beej Sanjiboni (20%) + Sashayagavya (20%) + Panchagavya (3%); T10 = Beej Sanjiboni (10%) + Sashayagavya (10%) + Panchagavya (3%); T11 = Panchagavya (3%) and T12 = Water (control).
The initial status of available nutrients within the treatment organic solutions was analyzed before their application. The highest pH (10.0 ± 0.17) was recorded in T8 treatment followed by 8.54 ± 0.04 in T1, 8.40 ± 0.06 in T5, 8.01 ± 0.03 in T7 and 7.56 ± 0.03 in T11 but for the remaining treatments the values remain within the neutral range i.e., 6.50 to 7.50. Electrical conductivity is a measure (dSm-1) of the relative salinity of vermicompost or the amount of soluble salts it contains. The highest EC was recorded in T3 (7.8 ± 0.04) followed by T4 (7.4 ± 0.03), T10 (5.8±0.03) whereas the lowest of (0.5 ±0.05) was recorded in T12. In case of organic carbon content in percentage, the maximum was recorded in T7 (0.46±0.02) followed by T6 (0.38±0.01); T4 (0.36±0.02); T11 (0.28±0.01) while it was negligible in T12. Similarly, for available nitrogen percentage, the highest of (0.1092±0.00040) was recorded in T7 followed by T4 (0.04312±0.00004) but for the other treatments it was recorded as insufficient quantity culminating with the very negligible amount or nil in T8 and T12 treatments. Likewise, for available phosphorous content in percentage, the treatment T7 was recorded the highest of (0.0182±0.00070) followed by (0.0147±0.00040) in T2 but for other treatments it was very scanty amount with nearly nil in T5 and T8. The highest available K (%) was recorded in T2 (0.4453±0.00043) followed by T3 (0.02599±0.00007); T4 (0.024155±0.00002) and T1 (0.02088±0.00013) while for other treatments the base material contained inadequate amount of available K. In the case of C: N ratio, the highest of (130±3.00) was recorded in the base material of T6 treatment followed by T11 (16.13±0.04); T10 (12.28±0.06); T9 (10.85±0.10); T5 (8.46±0.08); T4 (8.35±0.12) and the lowest of (2.35±0.05) was recorded in the base material of T1; whereas, T8 and T12 treatment’s base materials recorded nil C: N ratio.
The mean values of different nutrient components present in vermicompost under different treatment conditions were also studied in the present investigation. Most of the cases, pH values remain within the neutral range except for the T8 where it was recorded slightly higher (7.59±0.08). Contrastingly, most of the cases the pH values become decreased as compared to pH values of their respective base treatment materials. These findings are expected because it was earlier reported that during composting the pH values gradually decreased up to a certain level. The peculiar results were found in the case of EC values where it becomes either increased or decreased as compared to their respective base materials that recorded either less or more amount of EC values, respectively. The maximum value of EC (dS/m) was recorded in T2 (2.43±0.04), on the contrary, the treatment T6 recorded the lowest value of 1.67±0.16. However, the treatments had no significant difference in EC values among the treatment conditions under studied. In the case of organic carbon content (%), the highest of 19.62±0.40 was recorded in T7 whereas the lowest of 12.60±0.32 was recorded in T12 with significant difference even at 0.01 probability level among different treatments. For the available nitrogen percentage, the maximum value was recorded in T1 (1.18±0.06) followed by T7 (1.07±0.04) with the lowest of 0.89±0.01 in T8. The significant difference for available nitrogen percentage among different treatments, justified the practicability of this experiment. In case of available phosphorous content in percentage, the treatment T7 recorded the highest value (0.51±0.01) as against the lowest of (0.20±0.01) in the case of T12. Here again, the observations were recorded significant difference even at 0.01 probability level among different treatment conditions. The available potassium (%) in vermicompost derived from the experiment by the application of easily available organic solutions as different treatments was estimated and the finding showed that the highest K (%) in T2 (0.52 ± 0.01) as against the lowest of 0.38 ± 0.01 in T9. This parameter recorded significant difference in K (%) in different samples of vermicompost produced under different treatment conditions. The C: N ratio of 20.36±0.52 was recorded as the highest value in the case of T11 followed by 20.10±0.27 in T10 but it was recorded as the lowest of 12.79±0.62 under T1 treatment condition.
The mean values of different physical parameters of earthworms under different treatment conditions were also determined in this study. Most of the characters were registered non-significant except earthworm population under different treatment situations. However, the highest weight (0.90±0.08) g of earthworm was recorded in T7 and T10 treatments as against the lowest (0.47±0.03) g in the case of control treatment i.e., in T12. T7 and T10 treatments recorded the highest individual weight of earthworm. There is no significant difference in length of individual earthworm also but the highest value of (7.40±0.35) cm was recorded in T4 as against (6.33±0.04) cm in T8. Similarly, non-significant difference among different treatments was recorded in the case of circumference of individual earthworm but the highest value of (1.83±0.30) cm was recorded in T10, whereas T2 treatment recorded the lowest value of (1.17±0.42) cm. In case of earthworm population, significant difference was recorded among different treatments with the highest value of (528±6.00) in T10 followed by (522±11.14) in T11; (506±4.16) in T1, whilst the lowest value of (430±11.32) was recorded in T8. These findings showed that earthworm population was influenced towards the positive direction by the C/N ratio of the treatment materials up to certain level i.e., 12 to 16.
The correlation among different nutritional parameters of vermicompost as well as physical parameters of earthworms derived from different treatments was estimated. The results showed that pH value of vermicompost recorded no significant correlation with other parameters under studied but the highest positive correlation (r= 0.405) was recorded with available K (%) of vermicompost. Similarly, the negative but non-significant correlation (r = -0.452) was recorded between pH and available P (%) of vermicompost. The study also revealed that positive and significant correlation between EC (dS/m) and available K percentage (r=0.530; P˂0.05). The result is expected because EC depends on the amount of salt of any metal present in particular sample of vermicompost. The findings also inclined that negative but significant correlation (r= -0.547; P˂ 0.05) was recorded between EC and circumference of earthworm. That indicated the increase the concentration of salt in vermicompost is negatively correlated with the growth rate of earthworms. In the case of organic carbon content, the highly significant correlations were recorded with individual weight of earthworm (r= 0.802; P˂ 0.01) and C: N ratio (r=0.880; P˂ 0.01) of vermicompost derived from different treatments. The next highest but positive and non-significant correlation was recorded between OC (%) and earthworm population (r = 0.307). Correspondingly, significant positive correlation was recorded between available N (%) and individual average length of earthworm (r=0.639; P˂0.01). Contrastingly, negative but significant correlation was recorded between available N (%) and C: N ratio (r= -0.530; P˂ 0.05), that signified the reciprocal relation between these two parameters. This type of finding is obvious because the level of increasing or decreasing of nitrogen is directly related with the decreasing or increasing trend of C: N ratio, as N is the denominator for determining the C: N ratio. The findings also revealed that no significant correlation was recorded between available phosphorous and rest of the characters under studied. But available potassium recorded negative but highly significant correlation with the circumference of earthworm (r = -0.605; P˂ 0.01). Among the physical parameter of earthworm, individual weight of earthworm recorded positive and significant correlation with the C: N ratio (r = 0.597; P˂ 0.05). This observation was expected because biomass content of earthworm is associated with higher levels of C: N ratios. The other parameters under studied in the sub head physical parameters such as average length of individual earthworm, average circumference of individual earthworm and earthworm population under different treatment situates recorded positive as well as negative but non-significant correlation with rest of the parameters under studied. The non-significant but positive correlation was recorded between earthworm population and C: N ratio (r = 0.171), indicated more earthworm population under higher level of C: N ratio up to a certain level.
Keywords: Nutritional Status of Vermicompost, Organic Solutions, Composting process, C: N Ratio