Evaluation of critical nitrogen and phosphorus models for maize under full and limited irrigation conditions

Abstract

Proper nitrogen (N) fertiliser application rates and timing of application, coupled with optimum irrigation management can improve the sustainability of maize production and reduce the risk of environmental contamination by nutrients. The impact of full and limited irrigation and rainfed conditions on in-season maize (Zea mays L.) shoot biomass nutrient concentration and critical N and phosphorus (P) indices were evaluated using a combination of measured nutrients and critical N and P models in south central Nebraska in 2009 and 2010. Four irrigation treatments [fully-irrigated treatment (FIT), 75% FIT, 60% FIT and 50% FIT) and rainfed] were imposed. Irrigation regimes impacted the shoot biomass N concentration. The shoot biomass N concentration was above the critical N (Ncrit) concentration throughout the growing season under FIT and 75% FIT and was below the Ncrit value for the most limited irrigation (60% FIT and 50% FIT) and rainfed treatments. Nitrogen nutrient index (NNI) varied from 0.68 to 2.0. Biomass N concentration was below Ncrit [i.e., NNI<1] from 105 days after planting (DAP) to harvest under rainfed and 50% FIT and from 114 DAP to harvest under 60% FIT. Overall, the FIT and the 75% FIT had NNI values greater than 1.0 throughout both growing seasons. Phosphorus concentration, which decreased with biomass accumulation and irrigation amounts, varied from 1.0 to 4.8 g kg -1 , with FIT having the highest biomass P concentration. The critical N model combined with NNI can be used to evaluate N and P in maize for in-season nutrient diagnosis under the conditions presented in this research.

Plant nutrient removal and soil residual chemical properties as impacted by maize planting date and density

“…Heckman et al [ 54 ] reported maize grain N, P, and K concentrations of 1.29, 0.38, and 0.48%, respectively, which are higher than the finding of the present study regardless of the planting density and the planting date. The decreasing trend of grain nutrients with plant density is the dilution effect [ 21 , 55 , 56 ]. Maize grain nutrient uptake increased with plant density and decreased after 88,000 pph like the findings of Raymond et al [ 21 ] who reported that maize grain N uptake increased with plant density up to 74,000 pph and decreased at the highest density.…”

Plant Nutrition—New Methods Based on the Lessons of History: A Review

“…Moreover, the critical phosphorus concentration in plant tissues (P c ) of wheat calculated based on shoot biomass significantly differs among locations, whereas the location or region (Canada, Finland, and China) does not significantly affect this relationship if the P c is described as a function of the shoot nitrogen concentration [ 213 ]. Djaman and Irmak [ 214 ] further extended this procedure by calculating the critical phosphorus concentration in maize shoot biomass in combination with the critical nitrogen model (P c and N c ), resulting in a more robust tool for determining the critical nitrogen and phosphorus in maize. Most of the calculations of the dilution curves cover the nutrient concentration determined in the whole shoot biomass.…”

Assessing corn recovery from early season nutrient stress under different soil moisture regimes

“…Higher nutrient uptake levels have mainly been observed under adequate or fully irrigated conditions, while lower nutrient uptake is typical under water-limiting conditions ( Setiyono et al., 2010 ; Djaman et al., 2013 ; Faloye et al., 2019 ). For instance, Djaman and Irmak (2018) observed reduced nitrogen (N) uptake when corn was irrigated below 75% of fully-irrigated treatment, with the fully-irrigated treatment being irrigation scheduling at 60% of total available water. The authors observed similar results for phosphorus (P) ( Djaman and Irmak, 2018 ).…”

“…The root length and K influx were also reduced by about 50% under the low soil water conditions ( Seiffert et al., 1995 ). The lower nutrient uptake under water stress is usually due to decreased nutrient transport by mass flow and diffusion ( Seiffert et al., 1995 ; Buljovcic and Engels, 2001 ; Djaman and Irmak, 2018 ). Thus, nutrients that are preferentially taken up by the mass flow pathway tend to restrict plant growth the most under dry conditions.…”

“…For instance, Djaman and Irmak (2018) observed reduced nitrogen (N) uptake when corn was irrigated below 75% of fully-irrigated treatment, with the fully-irrigated treatment being irrigation scheduling at 60% of total available water. The authors observed similar results for phosphorus (P) (Djaman and Irmak, 2018). Also, Seiffert et al (1995) observed reduced potassium (K) uptake in corn with decreasing soil water content.…”