Vertical distribution of gas exchanges and their integration throughout the entire canopy in a maize field

2021 ◽  
Author(s):  
Zhenzhu Xu ◽  
Guangsheng Zhou ◽  
Qijin He
Keyword(s):  
Vertical Distribution ◽  
Gas Exchanges ◽  
Maize Field

Influence of NPK fertilization on weed flora in maize field

2014 ◽  
Vol 63 (1) ◽  
pp. 139-148 ◽  
Author(s):  
Éva Lehoczky ◽  
M. Kamuti ◽  
N. Mazsu ◽  
J. Tamás ◽  
D. Sáringer-Kenyeres ◽  
...  
Keyword(s):  
Plant Nutrition ◽  
Crop Production ◽  
N Availability ◽  
Weed Species ◽  
Negative Effects ◽  
Production Factors ◽  
Maize Field ◽  
Weed Flora ◽  
Npk Fertilization

Plant nutrition is one of the most important intensification factors of crop production. The utilization of nutrients, however, may be modified by a number of production factors, including weed presence. Thus, the knowledge of occurring weed species, their abundance, nutrient and water uptake is extremely important to establish an appropriate basis for the evaluation of their risks or negative effects on crops. That is why investigations were carried out in a long-term fertilization experiment on the influence of different nutrient supplies (Ø, PK, NK, NPK) on weed flora in maize field.The weed surveys recorded similar diversity on the experimental area: the species of A. artemisiifolia, S. halepense and D. stramonium were dominant, but C. album and C. hybridum were also common. These species and H. annuus were the most abundant weeds.Based on the totalized and average data of all treatments, density followed the same tendency in the experimental years. It was the highest in the PK treated and untreated plots, and significantly exceeded the values of NK fertilized areas. Presumably the better N availability promoted the development of nitrophilic weeds, while the mortality of other small species increased.Winter wheat and maize forecrops had no visible influence on the diversity and the intensity of weediness. On the contrary, there were consistent differences in the density of certain weed species in accordance to the applied nutrients. A. artemisiifolia was present in the largest number in the untreated control and PK fertilized plots. The density of S. halepense and H. annuus was also significantly higher in the control areas. The number of their individuals was smaller in those plots where N containing fertilizers were used. Contrary to them, the density of D. stramonium, C. album and C. hybridum was the highest in the NPK treatments.

The vertical distribution of tritium in water vapor in the lower troposphere

Tellus ◽  
1970 ◽  
Vol 22 (6) ◽  
pp. 699-706 ◽  
Author(s):  
Wayne E. Bradley ◽  
Glenn E. Stout
Keyword(s):  
Water Vapor ◽  
Vertical Distribution ◽  
Lower Troposphere ◽  
The Vertical Distribution
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