Performance of Aloe vera as Influenced by Organic and Inorganic Sources of Fertilizer Supplied through Fertigation R. Saha, S. Palit, B.C. Ghosh and B.N. Mittra Agricultural and Food Engineering Department Indian Institute of Technology, Dist Midnapore west Kharagpur 721302, West Bengal India Keywords: fertigation, vermicompost, vermiwash, chemical fertilizer Abstract An experiment was conducted on effects of organic and inorganic sources of fertilizer on performance of Aloe vera in Science and Technology Entrepreneur Park, Indian Institute of Technology, Kharagpur, India. The soluble fertilizers were supplied using fertigation. The organic source of fertilizer was liquid vermiwash, while inorganic N and K fertilizers were urea and muriate of potash in solution form. The result revealed that there was significant increase in biological and gel yields, plant height, number of leaves per plant and chlorophyll content with application of fertilizer as compared to no fertilizer treatment. Organic source of fertilizer in the form of vermicompost and vermiwash was found to be effective and comparable with inorganic source of fertilizer in increasing content of gel moisture, gel ash and aloin. The organic Aloe vera thus produced is expected to be a better marketable product. INTRODUCTION Aloe species (A. barbadensis Mill), a perennial succulent belonging to the family Liliaceae, are the source of drug aloe. Aloe is the yellow, bitter juice obtained by cutting the leaves at their base and the dark brown mass of drug aloe is obtained by evaporating the juice. Leaf gel or polysaccharides possesses pharmaceutical properties as well as are used in cosmetic industries. In India Aloe vera is traditionally grown in the natural habitats and there is no regular practice of Aloe vera cultivation by improved agrotechniques, particularly nutrient management. Aloe vera may respond differentially under varying sources and amounts of fertilizers. Merestala (1996) documented that for sustainable farming of crops, fertilizers would be preferred to inorganic sources to maintain soil health and quality production. Solid vermicompost and liquid vermiwash are proven organic source of fertilizers, which can be effectively used besides farmyard manure (FYM). Fertigation system is a proven practice for efficient and uniform application (inorganic and organic sources) of liquid fertilizers. A comparative study of growth, yield and quality of Aloe vera (grown in acid laterite soil) was therefore necessary under varying forms and concentrations of fertilizers. MATERIALS AND METHODS A field experiment was conducted in acid lateritic soil (ph 5.5) with low in organic carbon (0.62%), available N (42 ppm), available P (4.3 ppm) and available K (60 ppm). Aloe vera seedlings of 8-10 cm in height were transplanted in a prepared bed during June 2002 at a 50 cm spacing between plants and rows. Six fertilizer treatments were (i) Control (no fertilizer), (ii) FYM - 10.8 t/ha to supply N 40 kg/ha, (iii) vermicompost - of 3.175 t/ha + liquid vermiwash - 307 cu m/ha to supply N 80 kg/ha, and three concentrations of chemical fertilizer (iv) N P 60 K kg/ha, (v) N 80 P 40 K 80 kg/ha and (vi) N 40 P 20 K 40 kg/ha. The treatments were replicated three times in a Randomized Block Design (RBD). The sources of chemical fertilizers were urea (46% N), single super phosphate (16% P 2 O 5 ) and muriate of potash (60% K 2 O). Fertigation was done as per treatments to supply liquid vermiwash and the soluble chemical fertilizers urea and muriate of potash at 2% recommended concentration (Bachchhav, 1995) supplied at a Proc. WOCMAP III, Vol 2: Conservation Cultivation & Sustainable Use of MAPs Eds.: A. Jatisatienr, T. Paratasilpin, S. Elliott, V. Anusarnsunthorn, D. Wedge, L.E. Craker and Z.E. Gardner Acta Hort. 676, ISHS 2005 171
regular interval. Solid organic fertilizers like FYM and vermicompost and insoluble chemical fertilizers single super phosphate were mixed thoroughly in soil as basal application. A uniform moisture level was maintained in all treatments. The observations on growth, yield and quality parameters such as: moisture, N, P, K, Mg, Zn, Cu, Fe and Co, chlorophyll, gel and aloin content in leaves were recorded. The moisture content of gel was determined using METTLER LJ16 Moisture Analyzer. The concentrations of the micronutrients were analyzed by using GBC 932 atomic absorption spectrophotometer (AAS) and standard solutions (E-Merck) of different elements were used to prepare standard curves. The ash content of gel was determined using the muffle furnace (500 C for 24 hours). Analysis of aloin was undertaken by injecting. 20 µl of concentrated juice into a CAMAG high performance thin layer chromatograph (HPTLC) scanner. RESULTS AND DISCUSSION Growth and Yield Aloe vera height was higher by 25% under N P 60 K treatment compared to the control. Such increase was 19.6% greater when fertilizer was supplied through vermicompost + vermiwash (Table 1). Growth rate over a period of four months showed a maximum increase of 43% in N P 60 K and minimum of 23% in control. Maximum average number of leaves of 7.6 per plant was obtained at highest concentration of chemical fertilizer and that of 6.5 and 6 under vermicompost + vermiwash and FYM treatments, respectively (Table 1). Chlorophyll content in leaves was significantly higher under fertilizer treatments as compared to control. Maximum chlorophyll content of 39.13 mg/g was recorded under treatments supplied with organic sources and highest dose of chemical fertilizers at N P 60 K level. The above findings show that the Aloe vera responded to fertilizer dose in increasing the growth parameters. The biological yield and gel yield of Aloe vera (fresh weight) were significantly increased under different fertilizer treatments as compared to control. Maximum biological yield of 130 g/plant and gel yield of 61.4 g/plant were obtained under chemical fertilizer treatment at N P 60 K level, which was similar to the vermicompost + vermiwash treatment (Table 2). The growth and weight of Aloe vera root (fresh weight) attained maximum weight of 9.8 g/plant when the crop received fertilizer supplied through vermicompost + vermiwash, which was similar to the chemical fertilizer treatment at N P 60 K (Table 2). Higher dose of chemical fertilizer is expected to release greater quantity of nutrients particularly N, P, K at a faster rate and higher level and there by greater uptake by the plants which resulted in higher growth and yield parameters of Aloe vera. On the other hand incase of FYM, vermicompost and vermiwash the release of nutrients was gradual and slow after mineralization. Such controlled but regulated supply of nutrients increased uptake N, P, K which in turn, brought about higher growth and yield which was comparable with that of chemical fertilizer treatment. Quality There was insignificant variation in moisture content in gels under different fertilizer treatments (Table 3). However, the nutrient content, particularly N and K were increased with increasing levels of chemical fertilizer (Table 4). However, contents of P and Mg and micronutrients like Cu, Zn, Mn and Co were high under organic based fertilizer treatments. The Fe content was highest in chemical fertilizer treatment (Table 5). The aloin content derived from aloe was found to be higher in organic based fertilizers than inorganic ones (Fig. 1). Maximum aloin content of 19.62% was in FYM followed by 17.81% in vermicompost + vermiwash. In case of chemical fertilizer the aloin content was increased at fertilizer level N 80 P 40 K 80 or more as compared to control. The ash content of Aloe vera gel was a maximum in organic treatments of 0.178% in vermicompost + vermiwash treatment (Table 3). The ash content was decreased with 172
increased in levels of chemical fertilizer. CONCLUSIONS These results indicated that the Aloe vera responds differently to organic and inorganic sources. At equivalent nutrient level of N 80 P 40 K 80 organic sources of fertilizer treatments was superior to inorganic source. The information thus generated shows prospect of growing organic Aloe vera in a commercial cultivation as a better marketable product. Literature Cited Merestala, T. 1996. Abstract Bibliography of researches of Bio and Organic Fertilizers at Benguet State University 1975-1996. La Trinidad, Benguet. 53p. Bachchhav, S.M. 1995. Fertigation in India A case study. Dahlia Greidinger Intl. Symposium on Fertigation: 35-41. Tables Table 1. Plant height, number of leaves and chlorophyll content of Aloe vera under different fertilizer treatments. Number of Chlorophyll Plant height (cm) leaves content (mg/g) 60 Control 15.83 16.89 19.43 4.0 26.09 N 40 K 20 P 40 16.78 17.81 20.79 4.6 28.11 N 80 K 40 P 80 17.58 19.92 23.32 5.2 31.88 N K 60 P 19.63 20.66 24.26 7.6 39.13 Vermicompost 19.91 20.16 23.24 6.5 39.13 FYM 18.8 10.97 23.63 6.0 39.13 LSD (P=0.05) NS NS 1.468 0.14 2.94 Days after sowing Table 2. Gel, root weight and biological yield of Aloe vera under different fertilizer treatments at. Gel yield* Root weight* Biological yield* Control 36.0 4.0 75.0 N 40 K 20 P 40 43.0 6.3 97.3 N 80 K 40 P 80 49.5 7.0 110.7 N K 60 P 61.4 7.2 129.9 Vermicompost 59.5 9.8 121.0 FYM 52.6 5.9 116.7 LSD (P=0.05) 2.64 0.18 5.79 Days after sowing * Fresh weight 173
Table 3. Moisture, ash and aloin content of Aloe vera under different fertilizer treatments at. Moisture content in leaves (%) Moisture content in gel (%) Ash content in gel (%) Control 96.44 98.56 0.134 N 40 K 20 P 40 96.51 98.59 0.119 N 80 K 40 P 80 96.73 98.79 0.098 N K 60 P 96.66 98.73 0.081 Vermicompost 97.11 98.98 0.178 FYM 96.77 98.79 0.169 LSD (P=0.05) NS NS 0.021 Days after sowing Table 4. NPK content of Aloe vera leaves under different fertilizer treatments. N content (%) P content (%) K content (%) 60 60 60 Control 2.072 2.048 2.032 0.122 0.114 0.126 1.16 1.15 1.15 N 40 K 20 P 40 2.128 2.179 2.183 0.168 0.188 0.209 1.22 1.43 1.48 N 80 K 40 P 80 2.520 2.663 2.671 0.212 0.219 0.226 1.25 1.53 1.61 N K 60 P 2.632 2.787 2.812 0.270 0.274 0.259 1.20 1.86 1.88 Vermicompost 2.296 2.368 2.420 0.2 0.294 0.296 1.74 1.77 1.81 FYM 2.464 2.461 2.443 0.306 0.308 0.292 1.18 1.17 1.17 LSD (P=0.05) NS NS 0.267 NS NS 0.04 NS NS 0.24 Days after sowing Table 5. Micronutrient content of Aloe vera leaves at. Micronutrient content Mg (%) Zn Cu Mn Fe Co Control 0.708 75 6.2 450 119 Trace N 40 K 20 P 40 0.764 67 5.8 340 331 Trace N 80 K 40 P 80 0.832 77 6.4 393 250 3.0 N K 60 P 0.848 58 5.8 394 213 4.8 Vermicompost 1.44 86 9.0 492 154 6.4 FYM 1.48 79 8.2 239 139 9.6 Days after sowing 174
Figures 25 Aloin content (%) 20 15 10 5 0 Control N40P20K40 N80P40K80 NP60K Vermicompost FYM Fig. 1. Aloin content of Aloe vera under different fertilizer treatments at days after sowing. 175