Environmental variation in the long term pattern of germination from hard seeds of Lupinus varius

1967 ◽  
Vol 7 (26) ◽  
pp. 263 ◽  
Author(s):  
BJ Quinlivan

The long-term field germination pattern from hard seeds of sandplain lupin varied between sites. At Perth, where environmental conditions are almost ideal for the species, the hard seeds formed at the end of a growing season soften and germinate over the following five years. Some 15-20 per cent softened each summer and germinated with the following autumn rains. At Chapman, some 300 miles north of Perth in a drier more marginal environment for the species, all the hard seeds softened and germinated within two years. This wide site variation in the spread of germination from hard seeds is ascribed to environmental differences during the growing and dry seasons.


2011 ◽  
Vol 62 (10) ◽  
pp. 876 ◽  
Author(s):  
H. F. Zheng ◽  
L. D. Chen ◽  
X. Z. Han

Developing and assessing successful strategies to alleviate adverse impact of climate warming presents a new opportunity for sustainable agriculture and adaptation investment. Efforts to anticipate adaptation of cropping systems may benefit from understanding the global warming effects within decades. This study quantitatively examines the temperature warming impacts during, respectively, growing season and seed filling on soybean yields by using data from long-term field fertilisation experiments from 1987 to 2004. Here we report that grain yields significantly decreased with rising temperature during growing season, whereas the effects of increasing temperature at seed-filling stage on crop yields were significantly positive. The results indicate that a further temperature increment during seed filling appears to decrease soybean system’s risk of yield reduction. Importantly, we inferred that earlier occurrence of seed filling would increase the temperature of this period. The implication is that advancing the onset of soybean seed filling could be an effective adaptation option to global warming, providing an average yield benefit of ~14% per 10 days before the present date.



2020 ◽  
pp. 16-19
Author(s):  
Ya. Tsvei ◽  
R. Ivanina ◽  
Yu. Dubovyi

Goal. To study the effectiveness of fertilizers and crop rotation factor in controlling weed abundance in winter wheat crops. Methods. Long-term field and analytical. Results. Research data on the effectiveness of fertilizers and legumes predecessors in controlling weed abundance in winter wheat crops are presented. It has been established that the basis of weeding of winter wheat crops in the spring tillage phase was one- and dicotyledonous species, at the time of harvest — mostly by mass dicotyledonous. In the composition of the weeds, the largest competition for winter wheat crops for light and nutrients was created by Chenopodium album — 3.4—4.3 g/m2, Capsella bursa-pastoris L. — 0.6—4.0, Spergula vulgaris — 0.3—2.9, Fallopia convolvulus — 1.0—1.1 g/ m2. The use of mineral fertilizers significantly reduced the number of weeds in winter wheat crops at the beginning of the growing season and their mass at the time of harvest. Legume predecessors had not significant effect on the dynamics of weed development in winter wheat agrocenosis. Conclusions. The application of mineral fertilizers has been identified as an effective measure todecreaseweeds abundance and their mass in winter wheat crops. At the fertilizer doses N60Р60К60 the number of weeds in the spring tillage phase decreased by 6.3—6.5 times as compared to the control without fertilizers, and the mass of weeds at the time of harvest — by 2.6—3.0 times. Under the clover predecessor, the mass of dicotyledonous weeds at the time of harvest compared to the spring vetch was slightly higher with the predominance of Capsella bursa-pastoris L. — 2.5 g/m2 and Chenopodium album — 2.3 g/m2. Increasing the nitrogen dose for winter wheat from 60 to 90 kg/ha only in the clover rotation chain slightly increased the weed mass at the time of harvest. The total weeds mass in comparison with the nitrogen dose of 60 kg/ha increased by 2.7 g/m2.



2017 ◽  
Vol 243 ◽  
pp. 48-60
Author(s):  
Patricia Horn ◽  
André Schlichting ◽  
Christel Baum ◽  
Ute Hammesfahr ◽  
Sören Thiele-Bruhn ◽  
...  


1980 ◽  
Vol 58 (21) ◽  
pp. 2235-2240 ◽  
Author(s):  
Thomas J. Moser ◽  
Thomas H. Nash III ◽  
W. Dennis Clark

The gross photosynthetic response of Cladonia stellaris (Opiz.) Pouz. & Vezda., Cladonia rangiferina (L.) Wigg., and Cetraria cucullata (Bell.) Ach. to a continuous, long-term, in situ SO2 fumigation was monitored during the growing season at Anaktuvuk Pass, Alaska. The photo-synthetic capabilities of the test species were either destroyed or significantly reduced depending upon the SO2 stress gradient over the fumigation plot. Additional sampling of the plot 1 year after termination of the fumigation revealed no significant recovery in photosynthesis, and chlorophyll contents of the test species were significantly less than the controls.



2017 ◽  
Vol 257 ◽  
pp. 22-34
Author(s):  
Patricia Horn ◽  
André Schlichting ◽  
Christel Baum ◽  
Ute Hammesfahr ◽  
Sören Thiele-Bruhn ◽  
...  


Author(s):  
O.A. Lyapunova ◽  
◽  
M.A. Akhmedov ◽  
A.S. Andreeva ◽  
M.M. Magomedov ◽  
...  


1990 ◽  
Author(s):  
David M. Bailey ◽  
Stuart D. Foltz ◽  
Myer J. Rosenfield
Keyword(s):  


2018 ◽  
Vol 48 (4) ◽  
pp. 420-428
Author(s):  
Johana Juliet Caballero Vanegas ◽  
Karen Bibiana Mejía Zambrano ◽  
Lizeth Manuela Avellaneda-Torres

ABSTRACT Understanding the impacts of agricultural practices on soil quality indicators, such as enzymatic activities, is of great importance, in order to advance in their diagnosis and sustainable management. This study aimed to evaluate the effect of ecological and conventional agricultural managements on enzymatic activities of a soil under coffee agroecosystems. The enzymatic activities were associated with the biogeochemical cycles of nitrogen (urease and protease), phosphorus (acid and alkaline phosphatase) and carbon (β-glucosidase), during the rainy and dry seasons. Physical-chemical soil proprieties were also assessed and related to resilience scores linked to the climatic variability reported for the areas under study. The activities of urease, alkaline and acid phosphatase and ß-glucosidase were statistically higher in ecological agroecosystems than in conventional ones. This may be attributed to the greater application of organic waste in the ecological environment, as well as to the absence of pesticides and synthetic fertilizers, which allow better conditions for the microbial activity. The resilience scores to the climate variability that showed the highest correlations with the assessed enzymatic activities were: the farmers' knowledge on soil microorganisms, non-use of pesticides and synthetic fertilizers and non-dependence on external supplies. It was concluded that the enzymatic activities are modified by the management systems, being specifically favored by the ecological management. This agroecosystem, in the long term, ensures an efficient use of the soil resources, with a lower degradation and contamination.



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