Effect of nitrogen form on maize response to drought stress

Abstract

Two hybrids of maize (Zea mays L.) differing in resistance to drought, were grown in chernozem soil in a greenhouse and were fertilized with two different forms of nitrogen: Ca(NO3) 2 and (NH4)2SO 4 in concentrations corresponding to 100 kg of N ha z. After emergence of the 4th leaf, plants were exposed to drought. During the drought period, the parameters of plant water status (water potential, osmotic potential, turgor pressure and relative water content) and chlorophyll a + b concentration were monitored every two days. N and K concentration and accumulation over the drought period were also monitored.Next to differences in adaptability of the two hybrids to drought, the results demonstrate different adaptability of NH 4 and NO3-treated plants within each hybrid. NH4-plants of each hybrid maintain higher turgor pressure during the drought by better osmotic adaptation. Especially significant differences appear between chlorophyll (a + b) values of NH 4 and NO3-treated plants and as affected by drought. Chlorophyll concentrations of NH4-plants are higher than those of NO3-plants both in control and droughted plants. NH 4 plants show a characteristic initial chlorophyll increase at the beginning of the drought period while in N O 3 plants chlorophyll constantly decreases throughout the whole drought period. The influence of the nitrogen form on chlorophyll concentration changes during drought does not appear to be affected by regulation of the K concentration. ~2C

Drought Responses on Physiological Attributes ofZea maysin Relation to Nitrogen and Source-Sink Relationships

“…NH 4 treated plants maintain the high turgor by improved osmotic adjustment under drought stress. Whereas, chlorophyll a, b values significantly higher in NH 4 treated plants compared to NH 3 treated plants in which chlorophyll content decreased throughout the drought stress [23]. Similar work Zhang et al [101] indicated increased NO 3 nutrition played a favored anti-oxidative metabolic role, as compared with NH 4 nutrition, in the plants thereby increasing tolerance to drought stress.…”

“…Moreover, shortage and N excess affect assimilate partitioning between vegetative and reproductive organs [22]. Mineral nutrition influences the physiological response of plants to water stress [23]. While Waraich et al [24] discussed the role of macro-and micronutrients to decrease the adverse effect of drought in crop plants.…”

Nitrogen Sustains Seed Yield of Quinoa Under Intermediate Drought

“…It is also possible that cells from non‐fertilized plants may accumulate osmotically active substances (K + ) as it was found in maize with low doses of nitrate and ammonium (Mihailović et al. ).…”

Evaluation of Spring Wheat (20 Varieties) Adaptation to Soil Drought during Seedlings Growth Stage

“…The reduction of chlorophyll and carotenoid pigments was rather low, which may be indicative of a moderate intensity of drought stress. On the other hand, chlorophyll content in the wheat leaves during drought is dependent on the type of N ions present in the nutrient solution [26]. An initial increase of the chlorophyll content during drought took place in the presence of NH 4+ , which was followed by a decrease in severity of the drought.…”