AbstractA field trial consisting of four granule formulation doses and five liquid formulation sprays of a seaweed extract from Ascophyllum nodosum commercially known as Biovita, along with the recommended dose of nitrogen (N)–phosphorus (P)–potassium (K), was conducted during 2008 and 2009 in BHU, Varanasi, India, to evaluate its effect on wheat (var. HUW 468) under a no-tillage system. Among the granule doses, the 10 kg ha−1 basal application and the two liquid sprays of 500 cm3 ha−1 each at 25 and 50 days after sowing significantly improved the performance of wheat. On an average under these two treatments, the greatest grain and straw yields were observed were 3454.5, 3446.5 and 5187.5, 5220.0 kg ha−1, respectively. The greatest protein content was found when further high doses of extract were applied. A faster decomposition of the paddy residue was also observed as indicated by an earlier decline in carbon (C)/N ratio of the soil in the treated plots.Keywords: Residue decompositionseaweed (Ascophyllum nodosum) extractwheatzero tillage
A field experiment was conducted at the Agricultural farm of Visva-Bharati University, Birbhum, West Bengal during Pre-kharif (Summar) season of 2012, to study the effect of foliar spray of seaweed extracts (prepared from Kappaphycus alvarezii & Gracilaria crassa) on the growth and productivity of black gram. The foliar spray was applied thrice at different concentrations (0, 5.0, 7.5, 10.0 and 15.0% v/v) of seaweed extracts. Foliar applications of seaweed extracts significantly enhanced the growth and yield attributes. The highest grain yield was recorded with applications of 15% Kappaphykus + recommended dose of fertilizer which at par wth 15% Gracilaria extracts + RDF resulting in an enhanced by 51 and 44% grain yield, respectively compared to the water applied plots. The highest straw yield was also achieved with the application of 15% seaweed extracts. The nutrient uptake (N, P and K) which influenced due to the application was also with seaweed extract.
Transport of phosphorus (P) from agriculture often causes eutrophication of surface water systems, which is particularly a concern in alluvial soil regions because of coarse texture and intermediate water and cation exchange capacity. Organic residues are increasingly being applied to soil because of their ability to increase soil organic carbon that also improves soil physical, chemical and biological properties. However organic manures contain variable amounts of phosphours, which upon mineralization gets released, and is of environmental concern. To evaluate the risk of P losses, an experiment was carried out in an alluvial soil with three manures viz., farm yard manure (FYM), oil cake and pig manure, incubated at the rate of 4, 40, 80 t ha-1 for a period of 2, 72, 168, 336, 480, 1440, 2160 hours at constant temperature and moisture and net phosphorus mineralized was evaluated. It was found that the three manures differed widely in their C, N and P content and C/N and C/P ratios and consequently the mineralization pattern differed. FYM had higher C/P ratio as compared to oil cake and pig manure; consequently the net P mineralized in pig manure was the highest at all rates of P addition followed by oil cake and FYM throughout the time intervals studied. It was concluded the there was greater risk of P losses from high doses of pig manure addition in alluvial soils as compared to oil cake and FYM. Hence it was suggested that manures with different C/P ratios could be mixed to maintain a reasonably high P supplying capacity in soil at the same time the risk of P losses could be avoided.
A field experiment was conducted during 2007-10 at the Central Sericultural Research and Training Institute, Berhampore (West Bengal), under irrigated Gangetic alluvial soil conditions, to study the effect of various organic nutrient management packages on soil health, growth attributes, leaf yield, leaf quality and economic gain in newly evolved, triploid, high yielding, recommended and popular S 1635 mulberry ( Morus alba L.). Analysis of NPK status of soil was found to be improved in recommended practice, while available N was found marginally lower and available P and K were found higher in all the organic nutrient management packages over initial status. Analyzed data of three years (15 crops) with 7 treatments and 3 replication revealed that the effect of the treatments was found significant on plant height, branches/plant, leaves/plant, leaf area, leaf area index, leaf- shoot (%), leaf yield, leaf moisture, total chlorophyll and total soluble protein content in leaves. Maximum branches/plant was found in organic package (30 mt vermicompost/ha/year), while it was next best in leaves/plant, leaf yield (almost similar with integrated nutrient management package), total soluble protein and total soluble sugar content in leaves. During 3 rd year, the overall leaf yield in organic packages with vermicompost, vermicompost plus vermiwash and integrated nutrient management package was found at par with recommended practice and obtained marginally higher (6.4%) leaf yield in vermicompost package. It was further noticed that the increase level in leaf yield with vermicompost package was reached at the tune of 32.57% in 2 nd year over 1 st year and 39.95% in 3 rd year over 2 nd year which was maximum among other treatments. Moreover, about 10.5% leaf yield was increased in vermicompost package during winter crops (November and February) of 3rd year. The economic gain on 3 rd year leaf yield revealed that the organic package performed better in respect of about 6.4% more quality leaf yield (45.3 tonnes/ha/year), maximum net profit (Rupees 22 697/ha/year) and return/ rupee investment (1.33) with marginally higher expenditure (Rupees 67 931.13/ha/year) over recommended package.