Nitrogen Accumulation and Translocation for Winter Wheat under Different Irrigation Regimes

Abstract

The translocation of pre-anthesis nitrogen to the grain is an important source for winter wheat. The relation between the nitrogen translocation and irrigation regime was studied in the field under a rain-proof trough shelter. Nitrogen (N) translocation amount, N translocation efficiency decreased with a decline in irrigation amount or by excessive irrigation. Compared with different organs, the leaf and stem had higher N translocation amounts, and contributions to grain for both cultivars -Jinan 17 and Lumai 21, indicating that stem also is a major N source for grain development. The contribution of pre-anthesis total above ground N to grain N ranged from 57 to 76 %, indicating the importance of pre-anthesis storage of N for achieving high grain N concentrations. Grain nitrogen and yield (kg ha )1 ) were positively and significantly correlated with the N translocation amounts and contributions, respectively, suggesting that the sink strength may be involved in the translocation of N from a vegetative organ to the grain. N harvest index (NHI) was significantly correlated with N translocation efficiency, suggesting that the latter is a prerequisite for increasing grain N and improving grain quality. The experiment showed that N translocation status is enhanced by better irrigation practices, but limited by severely deficient or excessive irrigation.

Novas bactérias diazotróficas endofíticas na cultura do trigo em interação com a adubação nitrogenada, no campo

“…O aumento da produtividade do trigo também pode estar relacionado com a maior massa de grãos em relação à fitomassa. Os índices de colheita para massa ou para N, que representam a relação entre a massa de grãos e a massa total da planta ou a quantidade acumulada de N no grão e a quantidade total de N na planta, são indicadores sensíveis da translocação eficiente dos compostos fotossintetizados da parte vegetativa para os grãos (Xu et al, 2005). Didonet et al (2000) demonstraram aumento do índice de colheita em plantas de trigo na presença de isolados de Azospirillum em relação à testemunha.…”

Nitrogen Rates and Water Stress Effects on Production, Lipid Peroxidation and Antioxidative Enzyme Activities in Two Maize (Zea mays L.) Genotypes

“…In addition to supplying a nutrient for plant growth, N application could improve drought tolerance of plants to enhance yields (Zaman and Das 1991, Van Schaik et al. 1997, Boutraa and Sanders 2001, Xu et al. 2005).…”

Theory and application for the promotion of wheat production in China: past, present and future

“…In irrigation management practice, improved irrigation regimes have been researched and widely applied. For example, based on results showing the enhanced translocation of assimilates stored in vegetable tissues to grain under moderate water deficit during the grain‐filling stage, properly reduced irrigation amounts and times can increase both WUE and N use efficiency (NUE) with no sacrifice in grain yield . The contribution of N to grain decreases with significantly reduced or excessive irrigation, implying that dramatically decreased and excessive irrigation may limit the N contribution of pre‐anthesis vegetative parts to grains, consequently leading to a decline in NUE and yield .…”