News Update on Nutrient Management Research: July – 2019

Biogeochemical nutrient cycles and nutrient management strategies

Nutrient loading by riverine input into water systems has enhanced by 6–50 times for the N load from pristine conditions to gift, whereas a 18–180 times increase has been discovered within the P load. Reductions within the magnitude relation of N to P delivery has additionally occurred with time. in an exceedingly review of nutrient limitation in water systems, it’s shown that a lot of water systems show P limitation within the spring, switch to N limitation within the summer with some estuaries displaying dissolved salt limitation of the spring phytoplankton bloom. Historical and up to date changes in nutrient loading and their impact on nutrient limitation have intense the talk on the management of nutrient delivery to estuaries from each agricultural and purpose sources, and on what nutrient (N or P) ought to be managed for in water systems. it’s hypothesized that potential reductions in P might facilitate atomic number 8 depletion particularly in deep estuaries and cut back quick growing macrophytes like protoctist genus sp., though P reductions most likely can have very little impact on summer pigment concentrations, a very important recreational management goal. Reductions in N loading ought to cut back summer pigment concentrations and improve the conditions for submerged aquatic vegetation and so improve system functioning. Finally, if solely P reductions ar pursued, that’s if we have a tendency to ar ready to cut back P specified it’s limiting year around in water systems, it’s doubtless that the export of N from water systems would increase to the bordering N-limited marine systems, so solely commerce the matter of increased production with eutrophication. [1]

Approaches and uncertainties in nutrient budgets: implications for nutrient management and environmental policies

Nutrient budgets of agroecosystems are created either (i) to extend the understanding of nutrient sport, (ii) as performance indicator and awareness raiser in nutrient management and environmental policy, or (iii) as regulation policy instrument to enforce a definite nutrient management policy in observe. This paper explores nutrient budgeting approaches and summarizes sources of uncertainty related to these approaches. potential implications of uncertainties related to the various methodologies and approaches for nutrient management and environmental policy are mentioned. 3 varieties of nutrient budgets are distinguished, i.e. farm-gate, soil surface and soil systems budgets. A farm-gate budget is that the most integrative live of environmental pressure, and looks best suited as environmental performance indicator. A soil surface budget is acceptable for estimating world wide web loading of the soil with nutrients. Soil system budgets account for nutrient inputs and outputs, exercise of nutrients at intervals the system, nutrient loss pathways and changes in soil nutrient pools; it’s the foremost careful budget and provides detailed data for nutrient management. Case studies for the dairy DE Marke indicate that the 3 budgeting approaches supplement one another. The accuracy and exactitude of the nutrient budget rely upon budgeting approach, information acquisition strategy and sort of agroecosystem. there’s typically a substantial quantity of uncertainty within the nutrient budget, because of numerous potential biases and errors, notably within the partitioning of nutrient losses. potential sources of biases are personal bias, sampling bias, mensuration bias, information manipulation bias and fraud. Sources of errors are sampling and mensuration errors. each biases and errors in nutrient budget estimates could result in confusion and wrong conclusions. Yet, there’s very little printed proof that uncertainties are taken under consideration in deciding. Uncertainties are typically smaller for a farm-gate budget than for a soil surface budget. Therefore, farm-gate budgets are most popular over soil surface budgets as policy instrument. Quantifying uncertainties requires: (a) system identification and analysis, (b) classification of uncertainties, (c) specification of distributions of chances of the varied sources victimisation Monte Carlo simulation, and (d) observance of the nutrient pools, inputs and outputs over time. Analyses of uncertainties in nutrient budgets could offer data regarding the weakest chain in establishing agri-environmental cause–effect relationships and, therefore, could assist to raised focus analysis efforts. information for the gas budget of Netherlands indicate comparatively massive uncertainties for the things denitrification and activity, with coefficients of variation >30%. lastly, there’s a desire for traditional procedures and pointers in nutrient budgeting and uncertainty analyses, to enhance the boldness in and pertinency of nutrient budgets. [2]

Development of phosphorus indices for nutrient management planning strategies in the United States

Phosphorus (P), a vital nutrient for crop and placental production, will accelerate fresh eutrophication, currently one in every of the leading water quality impairments within the u.  s.. In response, the U.S. Department of Agriculture and therefore the Environmental Protection Agency planned a replacement nutrient management policy, currently addressing P moreover as atomic number 7 (N), that every state should enact by 2008. There area unit 3 approaches that address P—agronomic soil take a look at P recommendations, environmental soil take a look at P thresholds, and a P index to rank fields in step with their vulnerability to potential P loss. There area unit several versions of the P index currently in use, demonstrating the strength and adaptability of the classification framework to higher target remedial measures. Of the 3 P-based approaches, the P classification approach has been most generally adopted with forty seven states victimization this approach to focus on P management. This paper charts the event of the classification approach, that ranks web site vulnerability to P loss by accounting for supply (soil take a look at P, fertilizer, and manure management) and transport factors (erosion, runoff, leaching, and property to a stream channel) and descriptions modifications created among states that replicate native conditions and policy. extra factors embody flooding frequency, atmosphere modifiers (texture, pH, P sorption, reactive metallic element [Al]), conservation practices, and priority of receiving waters. whereas computation of the ultimate index price is additive in twenty states, seventeen multiply supply and transport factors to outline essential supply areas. Most states (47) have maintained the first classification approach of assessing web site vulnerability to P loss, with indices in 3 states quantifying P loss. we have a tendency to demonstrate victimization 3 management situations (changing the time of applied manure, bank buffer institution, and reduced feed P ration) that overall P index ratings are often remittent, giving farmers a lot of choices for manure management than by merely reducing application rates. [3]

Impact of carbon inputs on soil carbon fractionation, sequestration and biological responses under major nutrient management practices for rice-wheat cropping systems

Major nutrient management systems for rice-wheat cropping were compared for his or her potential to credit organic carbon (C) to the soil, its fractionation into active (very labile, VLc; labile, Lc) and passive (less labile, LLc; non-labile, NLc) pools, and crop yield responses. A ten-year long experiment was wont to study effects of: (i) no inputs (Control, O), (ii) 100 percent inorganic fertilizers (F) compared to reduced fertilizers inputs (55%) supplemented with biomass incorporation from (iii) chance legume crop (Vigna radiata) (LE), (iv) manure (Sesbania aculeata) (GM), (v) yard manure (FYM), (vi) wheat stalk (WS), and (vii) rice stalk (RS). most C input to soil (as the share of C assimilated within the system) was in metric weight unit (36%) followed by RS (34%), WS (33%), LE (24%), and FYM (21%) compared to O (15%) and F (15%). Total C input to soil had an instantaneous result on soil C stock, soil C fractions (maximum in VLc and LLc), nonetheless the responses in terms of biological yield were controlled by the standard of the biomass (C:N magnitude relation, decomposition, etc.) incorporated. Legume-based biomass inputs accumulated most edges for soil C sequestration and biological productivity. [4]

Effect of Integrated Nutrient Management on Soil Enzymes, Microbial Biomass Carbon and Microbial Population under Okra Cultivation

A field experiment was conducted at the Experimental Farm, Department of farming, Assam Agricultural University, Jorhat throughout March to Gregorian calendar month 2016 to check the “Effect of integrated nutrient management on soil enzymes, microbic biomass carbon and microbic population underneath okra cultivation”. The results of the study indicated that there was the development in soil biological properties and soil enzymes altogether plots over the initial worth. However, the very best biological properties like microbic Biomass Carbon (MBC) (244.86 µg g-1), microorganism population (8.24 log cfu g-1 soil), plant population (3.89 log cfu g-1 soil), soil enzymes like dye di-acetate (FDA)  (7.28 µg dye g-1 soil h-1), phosphomonoesterase (PME) (50.15 µg p-nitrophenol g-1 h-1), Deydrogenase (DH) (136.90 µg TPF g-1 soil twenty four h-1), Arylsulphatase (14.16 µg p-nitrophenol g-1 h-1) and  Arylesterase activity (113.92 µg p-nitrophenol g-1 h-1) was found within the treatment T3 [at five hundredth counseled dose of N, P, K + Vermicompost at the speed of two t ha-1 (mixed with microbic consortium)]. enhanced in microbic population and soil protein activity is that the indicator of fine soil condition for crop growth. so the addition of organic manure and biofertilizers together with the reduced quantity of inorganic fertilizers ought to be advocated for maintaining high soil quality for extended the amount. [5]

Reference

[1] Conley, D.J., 1999. Biogeochemical nutrient cycles and nutrient management strategies. In Man and River Systems (pp. 87-96). Springer, Dordrecht. (Web Link)

[2] Oenema, O., Kros, H. and de Vries, W., 2003. Approaches and uncertainties in nutrient budgets: implications for nutrient management and environmental policies. European Journal of Agronomy, 20(1-2), pp.3-16. (Web Link)

[3] Sharpley, A.N., Weld, J.L., Beegle, D.B., Kleinman, P.J., Gburek, W.J., Moore, P.A. and Mullins, G., 2003. Development of phosphorus indices for nutrient management planning strategies in the United States. Journal of Soil and Water Conservation, 58(3), pp.137-152. (Web Link)

[4] Impact of carbon inputs on soil carbon fractionation, sequestration and biological responses under major nutrient management practices for rice-wheat cropping systems

Ajay Kumar Bhardwaj, Deepika Rajwar, Uttam Kumar Mandal, Sharif Ahamad, Bhumija Kaphaliya, Paramjit Singh Minhas, Mathyam Prabhakar, Rakesh Banyal, Ranbir Singh, Suresh Kumar Chaudhari & Parbodh Chander Sharma

Scientific Reportsvolume 9, Article number: 9114 (2019) (Web Link)

[5] Kumar, V., Saikia, J., Barik, N. and Das, T. (2018) “Effect of Integrated Nutrient Management on Soil Enzymes, Microbial Biomass Carbon and Microbial Population under Okra Cultivation”, International Journal of Biochemistry Research & Review, 20(4), pp. 1-7. doi: 10.9734/IJBCRR/2017/38868. (Web Link)

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