Co-situsapplication of controlled-release fertilizers to alleviate iron chlorosis of paddy rice grown in calcareous soil

Iron Nutrition in Field Crops

“…Zinc (Zn) deficiency is a more common problem in rice production, while in some cases there may be simultaneous deficiencies in both Zn and Fe. There are occurrences of Fe deficiency in rice in the U.S. under certain conditions: inadequate soil reduction due to low organic matter levels, calcareous subsoil conditions, and large ratios of phosphorus (P) to Fe, where low solubility iron phosphates form (Morikawa et al, 2004). Iron deficiency occurs in the Texas and Louisiana rice production areas in high pH, sandy soils with low soil Fe levels (Fred Turner, Texas A&M, Beaumont, TX, personal communication) and in areas of the Florida Everglades region on peat soils with low total Fe content where Fe fertilizer must be applied (Snyder and Jones, 1988).…”

Mutational reconstructed ferric chelate reductase confers enhanced tolerance in rice to iron deficiency in calcareous soil

“…After germination, the seedlings were transferred to 500 g of calcareous soil obtained from Takaoka City (Toyama, Japan) and containing 1 g of CFR-M2 fertilizer (25), and they were grown in a pot in a greenhouse under natural light conditions. For control soil conditions, bonsol (Sumitomo Chemical Company, Osaka, Japan) was used.…”

Generation and Field Trials of Transgenic Rice Tolerant to Iron Deficiency

“…Timing of the decrease in soil redox potential might account for the relatively small differences in grain parameters between transformants and NTs, despite the clearly inferior performance of NTs during early growth. Indeed, in a prior experiment, NT seedlings grown in the same calcareous paddy field showed severe chlorosis, and many seedlings died in the early stages before the Eh fell below 0 mV [38]. Therefore, it is crucial for rice in calcareous paddy fields to survive the early stages of growth, when enhanced MAs production greatly supports Fe acquisition.…”

“…A calcareous subsoil from Toyama Prefecture containing fossil shells (pH ∼9.2; [38]) was used to establish a paddy field in the quarantine area of the Field Science Center of Tohoku University (Osaki, Miyagi, Japan; 38°44' N; 140°4…”