Nutrient Uptake, Partitioning, and Remobilization in Modern, Transgenic Insect‐Protected Maize Hybrids

Abstract

Modern maize (Zea mays L.) hybrids coupled with improved agronomic practices may have influenced the accumulation and partitioning of nutrient uptake since the last comprehensive studies were published. The objective of this study was to investigate nutrient uptake and partitioning among elite commercial germplasm with transgenic insect protection grown under modern management practices. Plants were sampled at six growth stages and divided into four fractions for nutrient determination. Total nutrients required per hectare to produce 23.0 Mg ha−1 of total biomass with 12.0 Mg ha−1 of grain included 286 kg N, 114 kg P2O5, 202 kg K2O, 59 kg Mg, 26 kg S, 1.4 kg Fe, 0.5 kg Mn, 0.5 kg Zn, 0.1 kg Cu, and 0.08 kg B. A 10‐d period (V10–V14) denoted the maximum rates of accumulation on a per day basis for dry weight (439 kg), N (8.9 kg), P2O5 (2.4 kg), K2O (5.8 kg), Mg (2.2 kg), S (0.7 kg), Zn (14.2 g), Mn (18.0 g), B (3.3 g), Fe (95.3 g), and Cu (3.0 g). The majority of total uptake occurred post‐flowering for P, S, Zn, and Cu. Harvest index values of P (79%), S (57%), Zn (62%), and N (58%) were identified in the grain. These results provide much needed data on the nutrient uptake and partitioning of current hybrids, and provide an opportunity to further refine fertilizer method and timing recommendations for maize biomass and grain production.

Availability of fertiliser sulphate and elemental sulphur to canola in two consecutive crops

“…However, S inputs have decreased in many regions over the last decades because of a decrease in atmospheric S deposition due to stricter pollution control and because of a shift towards high-analysis S-free fertilizers. On the other hand, crop removal of S in new high-yielding varieties has increased (Bender et al 2013). As a result, S deficiency has become more frequent in many agricultural areas (Scherer 2001;Haneklaus et al 2008), resulting in an increased need for S fertilization (Ceccotti 1996).…”

Maize Yield Response to Zinc Sources and Effectiveness of Diagnostic Indicators

“…Similarly, Carsky and Reid (1990) analyzed whole-plant tissue Zn in 3-to 6-week-old plants and observed that tissue Zn concentration explained only 21% of the variability in grain yields. Maize Zn content at the eighth leaf stage represents less than 10% of the total Zn uptake at maturity (Bender et al, 2013), which explains the relative weakness of tissue testing as a Zn diagnostic tool. In another study that related tissue Zn concentration in 6-week-old plants to its available supply, Hiatt and Massey (1958) observed that plants showing severe deficiency symptoms were stunted and had a relatively high Zn concentration, while lowest tissue Zn concentrations occurred when maize deficiency symptoms were mild and plants grew more.…”

“…Zinc removal with the maize grain and harvest index is the largest among all micronutrients (Bender et al, 2013). Bender et al (2013) reported that 308 g ha −1 were removed with the grain and a 62% harvest index on average for six hybrids that yielded 12,000 kg ha −1 .…”

“…Zinc removal with the maize grain and harvest index is the largest among all micronutrients (Bender et al, 2013). Bender et al (2013) reported that 308 g ha −1 were removed with the grain and a 62% harvest index on average for six hybrids that yielded 12,000 kg ha −1 . Zinc deficiencies began to show up in the mid-20th century in the USA (Thorne 1957;Wear and Hagler 1963), and in 1966, the Trace Element Committee of the Council on Fertilizer Application indicated that Zn-deficient corn was reported in 20 states (Berger 1962), resulting from the increased use of macronutrient fertilizers and high corn yields (Alley et al 1972).…”

Evaluating Nitrogen Use Efficiency (NUE) Indices on the Background of Mineral Status of the Seed Crop at Maturity: a Case Study of Maize

“…The rate of nitrogen uptake in this particular stage is driven by balanced uptake of other nutrients, such as potassium, phosphorus, and magnesium [15][16][17][18][19][20]. In modern staygreen varieties, the amount of nitrogen taken up by maize at the beginning of flowering constitutes around 50% of its final uptake [4,5,21]. The amount of mineral nitrogen taken up by maize during the grain-filling period depends to a great extent, irrespective of nutrient supply, on crop capacity to its utilization [22][23][24].…”