Nano iron (Fe) complex is an effective source of Fe for tobacco plants grown under low Fe supply

Long-term mono-cropping and excessive chemical fertilizer application reduce water-stable soil aggregate stability and soil N and C stocks in tobacco production. This study tested the hypothesis that rotation and fertilizer type affected the proportion of water-stable aggregates and aggregate-associated soil organic carbon (SOC) and total soil nitrogen (TSN) concentrations. Two planting systems (tobacco mono-cropping and tobacco-maize rotation) with five fertilizer treatments (0 and 75 kg N ha −1 , 450 kg oil cake + 75 kg N ha −1 , 15,000 kg farmyard manure + 60 kg N ha −1 , and 3000 kg straw + 75 kg N ha −1) were established in 2007. After 10 years, rotation and fertilizer type significantly affected soil aggregates and associated SOC and TSN at different soil depths. Rotation significantly increased mean weight diameter (MWD) and geometric mean diameter (GMD); GMD increased with increasing soil depth. Rotation and organic fertilizer effectively increased the proportion of large macro-aggregates and MWD and GMD, while significantly reducing the proportion of micro-aggregates. The effect of fertilization type and rotation on the SOC content of large macro-aggregates was more obvious than that on TSN content, but there was no significant effect on SOC and TSN contents of aggregates < 250 μm. Rotation and organic fertilizer significantly increased SOC stock and total nitrogen of soil macro-aggregates (> 250 μm). However, this trend weakened with increasing soil depth and decreasing aggregate size. Rotation and organic fertilizers used in tobacco production stabilized the proportion of macro-aggregates in surface soil and maintained SOC and TSN better. Keywords Flue-cured tobacco. Rotation. Organic fertilizer. Water-stable aggregate. Yunnan Abbreviations SOC Soil organic carbon TSN Total soil nitrogen BD Bulk density MWD Mean weight diameter GMD Geometric mean diameter SOM Soil organic matter SOCS Soil organic carbon stock TSNS Total soil nitrogen stock * Congming Zou

Section: Introductionmentioning

confidence: 99%

Rotation and Organic Fertilizers Stabilize Soil Water-Stable Aggregates and Their Associated Carbon and Nitrogen in Flue-Cured Tobacco Production

Chen

Kawaguchi

et al. 2019

“…Moreover, sulfuric acid reacts with calcium carbonate and sodium bicarbonates, which are often abundant in these soils, increasing the CO 2 emissions from the soil to the environment. On the other hand, the prevention/cure of Fe chlorosis with Fe chelates is a widespread agronomical practice in orchards (Bastani et al 2018). Nevertheless, such an approach involves high costs and environmental and health risks (Granja and Covarrubias 2018).…”

Section: Introductionmentioning

confidence: 99%

Evaluation of FE-heme Applications or Intercropping for Preventing Iron Deficiency in Blueberry

Michel

Beyá-Marshall

Rombolà

et al. 2019

The aim of this investigation was to study the effectiveness and physiological implications of sustainable strategies to correct Fe chlorosis in blueberries, based on Fe-heme applications or intercropping with graminaceous species. The experiment was conducted in a blueberry orchard established on a sub-alkaline soil. The Fe-heme applications increased shoot length without increasing the leaf chlorophyll concentration, gaseous exchange, and fruit yield components in comparison with control plants. On the other hand, intercropping with graminaceous species increased the leaf chlorophyll concentration, photosynthetic activity, and fruit yield, with similar effectiveness to the Fe-EDDHA treatment. However, this management technique reduced the shoot length and leaf N, P, and K concentrations in the plants. The results obtained highlight the potential of intercropping with graminaceous species as a sustainable management technique to correct Fe chlorosis in blueberry. Further studies will need to select new graminaceous species characterized by low nutrient requirements in order to optimize the effectiveness of this management technique.

“…In calcareous soils, the bicarbonate ion (HCO 3 − ) aggravates the situation and is the most prevalent cause of Fe chlorosis in fruit tree crops. Soluble ferric (Fe 3+ ) and ferrous (Fe 2+ ) salts react rapidly with calcium carbonate to form Fe-hydroxides, which make Fe unavailable to plants (Bastani et al 2018;Granja and Covarrubias 2018;Pestana et al 2004). In nutrient solutions, HCO 3 − (added as calcium or sodium carbonate)…”

Section: Introductionmentioning

confidence: 99%

Can Bicarbonate Enhance the Performance of Carob Seedlings Grown in Nutrient Solutions with Different Fe Concentrations?

Gama

Correia

Saavedra

et al. 2019

The aim of this work was to assess the effect of bicarbonate (Bic) ion on the nutritional status and performance of carob-tree seedlings, a species that normally grows in calcareous soil without exhibiting iron chlorosis symptoms. Seedlings were previously grown in nutrient solution with a small concentration of Fe (0.5-1 μM) to induce a moderate chlorosis. Afterwards, two experiments were established: in experiment 1, plants were grown for 21 days in the following treatments: Fe deficiency (Fe0), 0.5 μM Fe, 5 μM Fe, and 5 μM Fe plus calcium carbonate (CaCO 3). After assessing these results, a second experiment was conducted for 91 days, with the following treatments: Fe0, 1 μM Fe, 40 μM Fe and 40 μM Fe plus CaCO 3 and sodium bicarbonate (NaHCO 3). Chlorophyll of young leaves, biomass and mineral composition of leaves, stems and roots were assessed in both experiments. The ferric chelate reductase root activity (FC-R) and the genetic expression of calmodulin-regulated Ca 2+-ATPase pump (ACA gene) were evaluated in experiment 2. Fe-deficient plants exhibited reduced growth and enhanced macronutrients in leaves. Root micronutrient homeostasis changed as an adaptive mechanism in carob. The addition of bicarbonate did not aggravate Fe chlorosis, as leaf chlorophyll increased significantly. Root FC-R activity and ACA gene expression was not enhanced under Fe deficiency induced by bicarbonate (Fe40 + BicNa) which suggest a positive effect of bicarbonate in the metabolism of this crop. Nevertheless, small Fe concentrations (Fe1) induced a higher ACA gene expression thus indicating some stress response signalling. Keywords Calmodulin-regulated Ca 2+-ATPase pump. Ceratonia siliqua L.. HCO 3 −. Iron chlorosis. Nutrients. Root FC-R