Heavy use of chemical fertilizers, pesticides and fungicides causes health hazards and environmental pollution, apart from imparting resistance to pathogens nad insects. Thus, sustainable agriculture is the answer to tackle various issues arising from excessive dependence on synthetic chemicals. Organic farming is not merely non- chemical agriculture, but is a system for integrating interactions between soil, plant, water and soil micro-flora and fauna. Organic farming keeps soil healthy by improving biological life therein and helps sustain yields (Lampkin, 1990). It is based mainly on principles of restoration of soil organic matter in the form of humus and increasing microbial population (Pathak and Ram, 2003). Bell pepper, being a high-value crop, is subjected to indiscriminate use of fertilizers and pesticides for realizing high yields. But, information on organic cultivation of bell pepper as of now is rather scanty. Hence, the present study was undertaken with to assess the response of bell pepper to organic sources of nutrients in relation to biological status of the soil. The experiment was carried out at Agricultural Research Station, Gangavati, during 2006 and 2007 in a fixed plot situated in the Northern dry zone of Karnataka (Zone- 3) that receives rain both from South-West and North-East monsoon. This zone also falls under Tungabhadra command area. Average rainfall received here was 357.4mm and 176.4mm during the cropping seasons of 2006 and 2007, Effect of organic cultivation of Capsicum annuum L. on soil microbial properties under open-field and shade-house conditions Vasant M. Ganiger, J.C. Mathad1, M.B. Madalageri, N.S. Hebasur2 and G. Bhuvaneswari Department of Vegetable Science, College of Horticulture University of Horticultural Sciences, Bagalkot - 587 103, India E-mail : vasantg.veg@gmail.com ABSTRACT Two bell pepper (Capsicum annuum L.) varieties, viz., California Wonder and Gangavati Local, were raised under nine completely organic nutrient sources, along with recommended package of practices, and, under completely inorganic nutrient sources. Irrespective of the variety and growing environment, there was substantial increase in total bacterial count (22.97% and 24.98%), population of fungi (20.23% and 20.23%), actinomycetes (36.89% and 36.83%) and mycorrhiza (44.63% and 29.40%) in open-field and shade-house conditions, respectively, in all the nutrient combinations where organic sources were used, compared to the inorganic treatment. All organic nutrient sources used were found to be similar in their effect on soil microbes. Key words: Capsicum, organics, shade-house, soil microbes, dehydrogenase activity J. Hortl. Sci. Vol. 8(1):103-106, 2013 Short communication 1Department of Horticulture, College of Agriculture, UAS, Dharwad, Karnataka 2Department of Soil Science, College of Agriculture, UAS, Dharwad, Karnataka respectively. The soil of the experimental site was medium black. Composite soil samples were collected from 0-25cm depth before and after the experiment and subjected to analysis for biological properties. The experiment included main treatments as two varieties of bell pepper, viz., California Wonder and Gangavati Local. Sub-treatments were organic source of nutrients, presented in Table 1. The experiment was laid out in split-plot design, with three replications. The experimental area was sown with sunhemp (Crotalaria juncea) about three months earlier to bell pepper and sunhemp was incorporated into soil 45 days before transplanting bell pepper. Sunhemp incorporation was done in all experimental plots except sub-plot treatments O 10 and O 11 . Subsequently, the plot area was brought to fine tilth by repeated ploughing and harrowing. The nursery area too was ploughed, harrowed and the soil brought to a fine tilth. Beds for raising nursery seedlings for organic nutrient-source treatment were prepared by incorporating well-decomposed FYM + sand + red soil. Beds for raising seedlings for inorganic treatment were incorporated with the recommended dose of inorganic fertilizer mix along with FYM (Anontmous, 2005) before sowing bell pepper seeds. To avoid seed and soil-borne diseases, bell pepper seeds were treated with Trichoderma viridae prior to sowing. Roots of thirty five day old seedlings 104 of bell pepper (except seedlings for O 10 and O 11 treatments) were dipped in a slurry containing biofertilizers, viz., Azospirillum, mycorrhizal and phosphorus solubilizing bacterial cultures, for ten minutes. The seedlings were transplanted to a shade-house. All the necessary care Table 1. Organic and inorganic sources of nutrients used O 1 Basal dose of 100% N equivalent (150 kg/ha) through FYM 50% (75 kg/ha) and Vermicompost 50% (75 kg/ha) O 2 Basal dose of 100% N equivalent (150 kg/ha) through FYM 50% (75 kg/ha) and Vermicompost 25% (37.5 kg/ha) as basal and top dressing after 45 DAT with 25% Vermicompost (37.5 kg/ha) O 3 Basal dose of 150% N equivalent (225 kg/ha) through FYM 50% (112.5 kg/ha) and Vermicompost 50% (112.5 kg/ha) O 4 Basal dose of 150% N equivalent (225 kg/ha) through FYM 50% (112.5 kg/ha) and Vermicompost 25% (56.25 kg/ha) as basal and top dressing after 45 DAT with 25% Vermicompost (56.25 kg/ha) O 5 Basal dose of 100% N equivalent (150 kg/ha) through FYM 50% (75 kg/ha) and poultry manure 50% (75 kg/ha) O 6 Basal dose of 100% N equivalent (150 kg/ha) through FYM 50% (75 kg/ha) and poultry manure 25% (37.5 kg/ha) and top dressing after 45 DAT with 25% poultry manure (37.5 kg/ha) O 7 Basal dose of 150% N equivalent (225 kg/ha) through FYM 50% (112.5 kg/ha) and poultry manure 50% (112.5 kg/ha) O 8 Basal dose of 150% N equivalent (225 kg/ha) through FYM 50% (112.5 kg/ha) and poultry manure 25% (56.25 kg/ha) as basal and top dressing after 45 DAT with 25% poultry manure (56.25 kg/ha) O 9 Basal dose of 150 kg N equivalent through FYM, in addition to 25 t/ha recommended FYM O 1 0 NPK 150:75:50 kg/ha inorganic fertilizer source and 25 t/ha FYM as per recommended package (Control 1) O 1 1 NPK 150:75:50 kg/ha inorganic fertilizer source only (Control 2) Varieties used: V1= California Wonder, V2= Gangavathi Local Table 2. Effect of nutrient source on total populations of bacteria, fungi and actinomycetes in bell pepper varieties grown under open- field conditions (pooled data) Nutrient source Total bacterial count (CFuX106/g) Total fungal count(CFuX104/g) Total actinomycetes count (CFuX104/g) V 1 V 2 Mean V 1 V 2 Mean V 1 V 2 Mean O- 1 54.10 55.12 54.61 24.17 26.00 25.09 30.06 29.41 29.73 O 2 55.81 52.57 54.19 23.18 23.91 23.55 30.99 29.63 30.31 O- 3 52.85 53.78 53.31 25.19 24.67 24.93 29.25 28.39 28.82 O- 4 53.04 54.56 53.80 24.14 25.41 24.78 31.77 31.79 31.78 O- 5 52.55 50.87 51.71 25.14 25.02 25.08 30.01 31.18 30.59 O- 6 52.86 50.85 51.85 25.69 24.81 25.25 30.39 30.38 30.38 O- 7 52.27 50.6 51.43 22.63 24.19 23.41 27.00 29.16 28.08 O- 8 53.88 54.25 54.06 23.11 24.18 23.65 27.36 29.33 28.34 O- 9 53.78 50.12 51.95 24.37 25.15 24.76 28.85 30.37 29.61 O- 10 41.26 40.32 40.79 20.44 20.53 20.49 19.63 18.94 19.28 O- 11 34.31 36.31 35.31 16.28 17.21 16.75 16.76 15.35 16.05 Mean 50.61 49.94 50.27 23.122 23.73 23.43 27.46 27.63 27.54 Initial Value 38.72 18.69 17.38 % increase over IV 22.97 20.23 36.89 CD (P=0.01) SEm± CD (P=0.01) SEm± CD at (P=0.01) SEm± Variety (A) NS 0.6638 NS 0.5973 NS 0.3264 Nutrient source (B) 6.09 1.6724 3.15 0.8635 3.79 1.0421 AxB 8.62 2.3651 4.45 1.2212 5.36 1.4737 AxB 7.43 5.36 4.25 NS = Non-significant; V1= California Wonder; V2= Gangavathi Local and cultural operations were followed to raise the bell pepper crop. Diseases and pests were, however, managed using products of animal or plant origin only (neem oil, NSKE 0.5%, NPV, Pseudomonas fluorescence, Nomuruea releyi, Trichoderma viridae, Hirestela thampane and Verticillium lecani) in the organic plots. Ten grams of soil samples were diluted serially, using sterile distilled water, to 10-3, 10-4 , 10-5 and 10-6 strengths. Aliquots of the one ml of appropriate dilution were plated. Total bacteria present were enumerated by growth on nutrient agar, fungi on Martins Rose Bengal agar and actinomycetes on Kusters agar medium. Plates were incubated at room temperature and counts were made at three days for bacteria, at five days for fungi and at seven days for actinomycets. Mycorrhizal spores from soil samples were isolated by wetsieving and decanting (Gerdemann and Nicolson, 1963). Dehydrogenase activity in soil was assayed by the method of Cassida et al (1969). Data generated from the experiments were statistically analyzed and interpreted, following Fisher’s method of Analysis of Variance, as suggested by Panse and Sukhatme (1967). Data in Tables 2 and 3 reveal a substantial increase in total bacterial count (22.97% and 24.98%), total fungal count (20.23% and 20.23%) and total actinomycetan count (36.89% and 36.83% ) in the experiment site after bell pepper cropping, in open and shade-house conditions, respectively, compared to the initial value. Bell pepper varieties did not J. Hortl. Sci. Vol. 8(1):103-106, 2013 Ganiger et al 105 Table 3. Effect of nutrient source on total bacterial count, fungal count and actinomycetan count in bell pepper varieties grown under shade-house conditions (pooled data) Nutrient source Total bacterial count (CFuX106/g) Total fungal count (CFuX104/g) Total actinomycetes count (CFuX104/g) V 1 V 2 Mean V 1 V 2 Mean V 1 V 2 Mean O- 1 40.33 42.33 41.33 17.53 18.57 18.05 23.6 22.27 22.93 O 2 40.67 41.37 41.02 16.33 16.97 16.65 20.53 22.23 21.38 O- 3 41.40 41.46 41.43 18.10 18.53 18.31 23.00 22.53 22.76 O- 4 41.00 41.30 41.15 18.47 17.63 18.05 22.13 24.77 23.45 O- 5 42.53 39.40 40.96 17.07 18.30 17.68 24.67 21.63 23.15 O- 6 37.93 38.76 38.34 17.13 16.93 17.03 20.50 20.40 20.45 O- 7 39.53 39.70 39.61 16.80 17.10 16.95 22.50 21.06 21.78 O- 8 40.10 40.73 40.41 16.13 16.23 16.18 19.90 22.60 21.25 O- 9 41.50 43.63 42.56 18.23 17.50 17.86 24.90 26.43 25.66 O- 10 29.33 29.53 29.43 15.17 15.07 15.12 17.27 18.00 17.63 O- 11 28.47 27.53 28.00 14.17 14.40 14.28 14.33 13.83 14.08 Mean 38.43 38.70 38.56 16.83 17.02 16.92 21.21 21.43 21.32 Initial Value 29.30 14.98 15.58 % increase over IV 24.98 20.23 36.83 CD (P=0.01) SEm± CD (P=0.01) SEm± CD (P=0.01) SEm± Variety (A) NS 0.720 NS 0.222 NS 0.393 Nutrient sources (B) 6.36 1.748 NS 1.126 3.88 1.065 A × B 9.00 2.473 NS 1.593 5.48 1.507 A × B 7.88 NS 4.58 NS = Non-significant; V1= California Wonder; V2= Gangavathi Local Table 4. Effect of nutrient source on total mycorrhizal count and dehydrogenase activity in soil after cropping season in bell pepper varieties grown under open-field conditions (pooled data) Nutrient Total mycorrhizal Dehydrogenase source count (No. of activity (µg TPF /g spores/100 g) soil/24 hrs) V 1 V 2 Mean V 1 V 2 Mean O- 1 135.45 133.85 134.65 4.04 3.80 3.92 O 2 129.58 130.28 129.93 3.64 3.69 3.66 O- 3 128.29 130.14 129.22 3.79 3.74 3.76 O- 4 132.86 130.50 131.68 3.80 3.63 3.71 O- 5 129.59 131.96 130.78 4.08 3.81 3.94 O- 6 127.66 130.37 129.02 3.79 3.73 3.76 O- 7 133.67 133.69 133.68 3.76 3.68 3.72 O- 8 137.21 133.04 135.13 3.71 3.72 3.71 O- 9 130.86 131.35 131.11 3.94 3.78 3.86 O- 10 108.67 109.74 109.21 3.00 2.89 2.94 O- 11 82.24 80.87 81.555 2.40 2.35 2.37 Mean 125.10 125.07 125.09 3.63 3.52 3.58 Initial Value 88.31 2.48 % increase over IV 44.63 30.72 CD SEm± CD SEm± (P=0.01) (P=0.01) Variety (A) NS 0.8672 NS 0.0089 Nutrient sources (B) 10.76 2.9554 0.19 0.0548 AxB 15.23 4.1796 0.28 0.0775 AxB 11.19 NS = Non-significant V1= California Wonder V2= Gangavathi Local significantly influence microbial count. Organic treatments showed significant increase in microbial count over inorganic treatments. However, the of various organic treatments were found to be at par for microbial count. There was substantial increase in total mycorrhizal count (44.63% and 29.40%) and dehydrogenase activity (30.72% and 8.87%) in the open and shade-house conditions, respectively, in organic treatments over the initial value (Tables 4 and 5). Results indicated that organic sources of nutrients significantly influenced soil mycorrhizal count as well as dehydrogenase activity compared to inorganic sources. However, there was no significant difference among organic sources of nutrients. Vermicompost and poultry manure are known to contain higher amounts of growth substances, vitamins and enzymes. This increased the bacterial population and root biomass, resulting in elevated amounts of exudates which, in turn, increased bacterial multiplication in the rhizosphere region. Present results are in agreement with those of Chitesh (2005) and Nandani (2006). Microbial count was higher in the treatments O 1 to O 8 compared to other treatments involving chemical fertilizers. Treatments O 1 to O 8 had higher dehydrogenase activity (2.62 to 2.97µl hydrogen evolved) compared to the inorganic nutrient source treatment O 11 (2.15µl hydrogen J. Hortl. Sci. Vol. 8(1):103-106, 2013 Organic cultivation of capsicum and soil microbial properties 106 Table 5. Effect of nutrient source on total mycorrhizal count and dehydrogenase activity in soil after cropping season in bell pepper varieties grown under shade-house conditions (pooled data) Nutrient Total Mycorrhizal Dehydrogenase source count (No. of activity (µg TPF /g spores/100 g) soil/24 hrs) V 1 V 2 Mean V 1 V 2 Mean O- 1 99.33 105.33 102.33 2.97 2.97 2.97 O 2 101.33 106.00 103.66 2.68 2.67 2.67 O- 3 102.66 102.33 102.49 2.63 2.65 2.64 O- 4 105.33 106.00 105.66 2.61 2.63 2.62 O- 5 97.33 93.33 95.33 3.08 3.03 3.05 O- 6 93.66 95.66 94.66 2.74 2.67 2.70 O- 7 95.33 92.66 93.99 2.77 2.70 2.73 O- 8 100.00 87.00 93.50 2.84 2.75 2.79 O- 9 110.00 105.66 107.83 2.95 2.79 2.87 O- 10 63.33 53.66 58.49 2.37 2.24 2.30 O- 11 44.66 41.33 42.99 2.14 2.17 2.15 Mean 92.08 89.90 90.99 2.51 2.46 2.48 Initial Value 50.38 2.26 % increase over IV 29.40 8.87 CD SEm± CD SEm± (P=0.01) (P=0.01) Variety (A) NS 1.896 NS 0.026 Nutrient sources (B) 14.72 4.056 0.24 0.065 A × B 20.89 5.736 0.33 0.092 A × B 19.45 0.29 NS = Non-significant V1= California Wonder V2= Gangavathi Local evolved). Higher enzyme activity in these treatments may be attributed to higher soil microbial population which was probably due to more substrates being available in the form of FYM, Vermicompost and poultry manure. Soil organic matter plays an important role in protecting soil enzymes which become immobile in the three dimensional network of clay and humus complex (Tabatabai, 1994). This reflects greater biological activity in the plot receiving these substrates and stabilization of extra-cellular enzymes with humic substances (Burns, 1982 and Colvan et al, 2001). These results of the experiment are also in conformity with findings of Gunadi et al (1999), Masciandaro et al (2000), Chitesh (2005) and Nandani (2006). REFERENCES Anonymous. 2005. Horticulture package of practices, University of Agricultural Sciences, Dharwad Karnataka, India Burns, R.G. 1982. Enzyme activity in soil: location and a possible role in microbial ecology. Soil Biol. 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Microbiological and biochemical properties, SSSA, Madison, USA, pp.775-833 (MS Received 17 September 2011, Accepted 15 June 2012, Revised 09 November 2012) J. Hortl. Sci. Vol. 8(1):103-106, 2013 Ganiger et al