Plant growth and aboveground production respond differently to late-season deluges in a semi-arid grassland

Oecologia ◽  
2019 ◽  
Vol 191 (3) ◽  
pp. 673-683 ◽  
Author(s):  
Alison K. Post ◽  
Alan K. Knapp
Keyword(s):  
Plant Growth ◽  
Late Season ◽  
Aboveground Production ◽  
Semi Arid

Evaluation of winter wheat management practices under semi-arid conditions

1992 ◽  
Vol 72 (1) ◽  
pp. 1-12 ◽  
Author(s):  
G. P. Lafond
Keyword(s):  
Plant Growth ◽  
Winter Wheat ◽  
Nitrogen Fertilizer ◽  
Growing Season ◽  
Late Season ◽  
Fungicide Application ◽  
Residual Nitrogen ◽  
Growing Conditions ◽  
Semi Arid ◽  
Growing Season Precipitation

A study was conducted to evaluate European cereal management techniques in winter wheat under semi-arid growing conditions. Combinations of rates and split applications of ammonium nitrate fertilizer with a plant growth regulator and/or a late season fungicide application were investigated using no-till "stubbled-in" production practices in two winter wheat cultivars, Norwin and Norstar at two locations over 3 yr. Nitrogen fertilizer gave the maximum yield when it was applied in mid-April. Split applications of nitrogen did not improve grain yields or grain protein concentration. A height reduction was observed with the use of plant growth regulators in both cultivars but no benefits were incurred due to the lack of lodging. The late season fungicide application had some effect on increasing kernel weight in both cultivars but rarely translated into a higher yield. Nitrogen and growing conditions had the largest effects on yield and the dilemma faced by producers is to correctly match nitrogen rates with environmental conditions given that the nitrogen has to be applied early in the spring. Available spring soil moisture and soil residual nitrogen provided little help in determining the rate of nitrogen giving the maximum economic yield because assumptions on growing season precipitation have to be made. It is suggested that nitrogen management be based on a risk analysis which would involve determining the probability of different levels of growing season precipitation for various climatic zones and soil types and the corresponding yield levels expected. Rates of nitrogen fertilizer would then be adjusted according to soil residual nitrogen levels and the risk the producer is willing to assume. This will require more extensive research and development of crop production models.Key words: Nitrogen fertilizer, Triticum aestivum L., intensive cereal management, propiconazole, chlormequat chloride, ethephon

scholarly journals A simple ecohydrological model captures essentials of seasonal leaf dynamics in semi-arid tropical grasslands

2009 ◽  
Vol 6 (5) ◽  
pp. 8661-8690
Author(s):  
P. Choler ◽  
W. Sea ◽  
P. Briggs ◽  
M. Raupach ◽  
R. Leuning
Keyword(s):  
Soil Moisture ◽  
Plant Growth ◽  
Linear Models ◽  
Nonlinear Models ◽  
Plant Cover ◽  
Spatial And Temporal Variability ◽  
Tropical Grasslands ◽  
Low Dimensional ◽  
Semi Arid ◽  
Leaf Dynamics

Abstract. Modelling leaf phenology in water-controlled ecosystems remains a difficult task because of high spatial and temporal variability in the interaction of plant growth and soil moisture. Here, we move beyond widely used linear models to examine the performance of low-dimensional, nonlinear ecohydrological models that couple the dynamics of plant cover and soil moisture. The study area encompasses 400 000 km2 of semi-arid perennial tropical grasslands, dominated by C4 grasses, in the Northern Territory and Queensland (Australia). We prepared 8 yr time series (2001–2008) of climatic variables and estimates of fractional vegetation cover derived from MODIS Normalized Difference Vegetation Index (NDVI) for 400 randomly chosen sites, of which 25% were used for model calibration and 75% for model validation. We found that the mean absolute error of linear and nonlinear models did not markedly differ. However, nonlinear models presented key advantages: (1) they exhibited far less systematic error than their linear counterparts; (2) their error magnitude was consistent throughout a precipitation gradient while the performance of linear models deteriorated at the driest sites, and (3) they better captured the sharp transitions in leaf cover that are observed under high seasonality of precipitation. Our results showed that low-dimensional models including feedbacks between soil water balance and plant growth adequately predict leaf dynamics in semi-arid perennial grasslands. Because these models attempt to capture fundamental ecohydrological processes, they should be the favoured approach for prognostic models of phenology.

scholarly journals Bioinoculants in Technological Alleviation of Climatic Stress in Plants

2021 ◽  
Author(s):  
Rafia Younas ◽  
Shiza Gul ◽  
Rehan Ahmad ◽  
Ali Raza Khan ◽  
Mumtaz Khan ◽  
...  
Keyword(s):  
Plant Growth ◽  
Cold Stress ◽  
Stress Proteins ◽  
Global Climate ◽  
Agricultural Practices ◽  
Plant Growth Promoting Rhizobacteria ◽  
Growth And Yield ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Semi Arid

Global climate change is leading to a series of frequent onset of environmental stresses such as prolonged drought periods, dynamic precipitation patterns, heat stress, and cold stress on plants and commercial crops. The increasing severity of such stresses is not only making agriculture and related economic sector vulnerable but also negatively influences plant diversity patterns. The global temperature of planet Earth has risen to 1.1°C since the last 19th century. An increase in surface temperature leads to an increase in soil temperature which ultimately reduces water content in the soil, thereby, reducing crop growth and yield. Moreover, this situation is becoming more intense for agricultural practices in arid and semi-arid regions. To overcome climatically induced stresses, acclimatization of plant species via bioinoculation with Plant Growth Promoting Rhizobacteria (PGPR) is becoming an effective approach. The PGPR are capable of colonizing rhizosphere (exophytes) as well as plant organs (endophytes), where they trigger an accumulation of osmolytes for osmoregulation or improving gene expression of heat or cold stress proteins, or by signaling the synthesis of phytohormones, metabolites, proteins, and antioxidants to scavenge reactive oxygen species. Thus, PGPR exhibiting multiple plant growth-promoting traits can be employed via bioinoculants to improve the plant’s tolerance against unfavorable stress conditions.

Sign in / Sign up

Export Citation Format

Share Document