Effect of organic and inorganic nutrient management on nutrient uptake by rice (Oryza sativa L.)

The field experiment was carried out at AICRP IFS Research Farm, Krishi Nagar, Jawaharlal Nehru Krishi Vishwa Vidyalaya, and Jabalpur (MP), India during Kharif season of 2016. The study was carried out to evaluate the suitable organic and inorganic nutrient for rice crop. The results revealed that grain yield, straw yield and nutrient uptake viz., nitrogen, phosphorus and potassium uptake by grain and straw of rice were higher with application of 100% NPK through fertilizers and 50% N through Vermicompost + 50% NPK through fertilizers, as compared to 100% N through Vermicompost, 75% N through Vermicompost, farmers practice N: 60, P: 30 through fertilizers + 3 tonnes FYM/ha, 75% N through Vermicompost + 25% NPK through fertilizers and absolute control.

Pertinent Nutrient Status in Soil and Water of Kargah and Napuras Streams in Gilgit Valley

Aims: To observe the status of salinity build up besides inorganic nutrient status at different sites in Kargah and Napuras streams of Gilgit valley. Study Design: one-way ANOVA means using LSD test. Place and Duration of Study: Kargah and Napuras streams and nearby village in Gilgit valley and the duration of the study was 3 months. Methodology: Soil and water sampling to analyze pertinent salinity parameters besides inorganic nutrient status. Results: Soil and water properties for important salinity parameters were normal at mid point after entering the village areas of Kargah and Napuras streams. Human activities especially to raise crops by applying fertilizers needs to monitor with a specific time scale in order to avoid salinity build up.

Cape Verde Frontal Zone in summer 2017: lateral transports of mass, dissolved oxygen and inorganic nutrients

The circulation patterns in the confluence of the North Atlantic subtropical and tropical gyres delimited by the Cape Verde Front (CVF) were examined during a field cruise in summer 2017. We collected hydrographic data, dissolved oxygen (O2) and inorganic nutrients along the perimeter of a closed box embracing the Cape Verde Frontal Zone (CVFZ). The detailed spatial (horizontal and vertical) distribution of water masses, O2 and inorganic nutrients in the CVF was analyzed, allowing for the independent estimation of the transports of these properties in the subtropical and tropical domains down to 2000 m. Overall, at surface and central levels, a net westward transport of 3.76 Sv was observed, whereas at intermediate levels, a net 3 Sv transport northward was obtained. We observed O2 and inorganic nutrient imbalances in the domain consistent with O2 consumption and inorganic nutrient production by organic matter remineralization, resulting in a net transport of inorganic nutrients to the ocean interior by the circulation patterns.

Harmful algal blooms as a sink for inorganic nutrients in a eutrophic estuary

Phytoplankton-mediated nutrient fluxes typically provide only pulsed relief to adjacent coastal waters during the productive period, with nutrient export increasing in the absence of substantial phytoplankton biomass. On the warm temperate coastline of South Africa, the Sundays Estuary is characterised by highly regulated freshwater inflow patterns, nutrient-enriched conditions, and resident harmful algal blooms (HABs). Given these attributes, the study objective was to investigate the effect of these phytoplankton blooms on fluvial inorganic nutrient dynamics. To assess uptake, we analysed inorganic nutrient (phosphate, ammonium, NOx) and phytoplankton concentrations in relation to salinity using data from 17 surveys. Property-salinity mixing diagrams and statistical analyses indicated a positive association between increasing phytoplankton biomass and decreasing NOx flux (p < 0.001), and to a lesser degree phosphate flux (p = 0.22), along the gradient from low-salinity inner estuary to high salinity outer estuary. High biomass HAB accumulations of Heterosigma akashiwo (>100 µg chl a l-1) represent significant removal of available NOx (~100%) and phosphate (>75%) during warmer conditions (>20°C). These events, together with continuous inorganic nutrient uptake during less severe bloom conditions, remove a substantial portion of annual NOx and phosphate loads (36.5 and 36.4% flux, respectively). Although this buffers inorganic nutrient loading to adjacent coastal waters, it also represents an emerging legacy pollution issue in the form of a benthic accumulation of organic material in bottom waters subject to recurrent hypoxia. Future management efforts should adopt an ecosystem-based approach centred around simultaneous restoration of hydrological variability and dual nutrient reduction strategies (N and P).

Crop nutritional management affects soil structure and soil functions at different scales.

&lt;p&gt;Soil organic matter is associated with important biological and physical functions. There are many theories to interpret this association, as yet there is not a fully developed understanding linking soil properties to nutritional management in arable systems.&lt;/p&gt;&lt;p&gt;We used X-ray computed tomography to analyse soil structure at the core and aggregate scale on the Broadbalk long term experiment (Hertfordshire, England). Here we present results of the treatments that have been under continuous wheat for 175 years. Corresponding to treatments that the only difference between the treatments is the nutrient management regime, with the exception of the baseline, or &amp;#8216;wilderness&amp;#8217; treatment in which the plot was left unmanaged and has returned to mature woodland since 1882. The other nutrient treatments correspond to inorganic fertiliser addition with and without phosphorus, farmyard manure, and no added nutrient.&lt;/p&gt;&lt;p&gt;At core scale (40 &amp;#181;m resolution) we capture macro pore structures that are responsible for convective flow, while the aggregate scale images (1.5 &amp;#181;m resolution) include structures responsible for retention of water by capillary forces.&amp;#160; Therefore, a comparison of images taken at the two resolutions 1.5 &amp;#181;m and 40 &amp;#181;m provides information on how soil partitions between drainage and storage of water, and therefore on the air water balance under different environmental contexts.&lt;/p&gt;&lt;p&gt;The results are presented as a state-space plot of simulated permeability vs. porosity for each treatment. We find that nutrient management resulted in two distinct states at aggregate scale corresponding to water storage potential. Inorganic nutrient management resulted in structures of lower porosity and lower simulated permeability. There was no significant difference between each treatment, or between these treatments and the treatment with no nutrient addition. By comparison, the wilderness and manure treatments had higher porosity and higher permeability, with no significant difference between them.&lt;/p&gt;&lt;p&gt;At core scale, the results are slightly different. Again, the inorganic nutrient management treatments had lower porosity and simulated permeability, with no significant difference between them, and between them and the treatment with no nutrient addition. However, the manure treatment had a significantly lower porosity and permeability than the wilderness treatment. We conclude that long-term cultivation with organic nutrient management results in a similar capacity for water storage and transport to roots than a wilderness control, but that long-term management using a purely inorganic nutrient regime results in a smaller capacity for water storage and a lower transport rate to roots. Organic inputs, roots and plant detritus ploughed into the soil after harvest had no significant impact. Infiltration potential is highest in the wilderness control, lower for the manure treatment, and lowest for the inorganic nutrient management treatment. Again, inputs of organic nutrients from plants had no significant impact. We interpret these findings in terms of a previously hypothesised self-organising feedback loop between microbial activity and soil structure.&lt;/p&gt;