scholarly journals OVERSOWING GRASSES ON SUNNY AND SHADY FACES

Author(s):  
J.G.H. White ◽  
G. Meijer ◽  
R.H.M. Langer

Eight grasses were oversown on steep north and south aspects at Hunua, North Canterbury, either initially with clovers or three years after oversowing clovers. On the north aspect, cocksfoot established and persisted best but ryegrasses were superior on the south aspect. Here the later sowing was much superior, as by then the original dense cover had disappeared, but on the north aspect time of grass introduction made little difference. Clover introduction resulted in a threefold increase in dry matter production on the south aspect, which produced double that of the north aspect. Ryegrasses raised yields still further, but depressed resident grass production.

2021 ◽  
Vol 9 ◽  
Author(s):  
S. M. Ayling ◽  
Jill Thompson ◽  
A. Gray ◽  
L. J. McEwen

In the United Kingdom, agricultural grasslands cover 40% of the land area, make up 89% of the total agricultural area and are an important land use for ecosystem services and food security. Climate change predictions suggest that the United Kingdom will experience more frequent and severe periods of drought that may impact these grasslands. As part of the Drought Risk and You (DRY) project, a field experiment in which rain shelters reduced precipitation reaching the vegetation by approximately 50%, was set up in the South West of England. The experiment ran for 3 years, from October 2015 to October 2018. The study was carried out at two locations in the catchment of the Bristol River Frome. Both sites were species-rich semi-natural pastures that had received no inputs of fertilizer or herbicide for many years. Automatic weather stations recorded environmental conditions, especially rainfall, within the experimental area. The existing agricultural management regimes were approximated by cutting the vegetation in the plots, by hand, at the appropriate times of year. The effect of rainfall reduction on plant growth was assessed by biomass sampling. At both sites, the rainfall reduction treatment had only small effects on total above ground dry matter production (biomass). These effects were much smaller than the year-to-year variation in total biomass. Our results suggested that well-established permanent pastures in the South West of England were able to tolerate a 3-year period of reduced water supply. The observed year-to-year variation in biomass demonstrated how important the timing of dry weather is for biomass production, and this will be reflected in effects on yield and quality of hay.


Author(s):  
B.R. Watkin ◽  
G.S. Robinson

In two experiments carried out at Massey University it was shown that 'Massey Basyn' Yorkshire fog gave similar dry matter yields to Ruanui, Ariki, and Manawa ryegrasses and promoated lamb liveweight gains similar to those ,obtained on Ruanui ryegrass pastures. Lamb birthweights were significantly lower on Yorkshire fog than on ryegrass pastures. Yorkshire fog was relatively slow to establish, but low grass production in the early stages was balanced by increased clover growth. The seasonal production of Yorkshire fog was well distribumted. Yorkshire fog suppressed white clover and volunter species more than did the ryegrasses, particularly in spring, when Yorkshire fog plots gave lower yields than ryegrass plots.


2005 ◽  
Vol 33 (1) ◽  
pp. 377-380
Author(s):  
Erzsébet Nádasy ◽  
Gábor Wágner

2019 ◽  
Author(s):  
Hamed D. Ibrahim

North and South Atlantic lateral volume exchange is a key component of the Atlantic Meridional Overturning Circulation (AMOC) embedded in Earth’s climate. Northward AMOC heat transport within this exchange mitigates the large heat loss to the atmosphere in the northern North Atlantic. Because of inadequate climate data, observational basin-scale studies of net interbasin exchange between the North and South Atlantic have been limited. Here ten independent climate datasets, five satellite-derived and five analyses, are synthesized to show that North and South Atlantic climatological net lateral volume exchange is partitioned into two seasonal regimes. From late-May to late-November, net lateral volume flux is from the North to the South Atlantic; whereas from late-November to late-May, net lateral volume flux is from the South to the North Atlantic. This climatological characterization offers a framework for assessing seasonal variations in these basins and provides a constraint for climate models that simulate AMOC dynamics.


2013 ◽  
Vol 38 (10) ◽  
pp. 1884-1890 ◽  
Author(s):  
Ren-He ZHANG ◽  
Dong-Wei GUO ◽  
Xing-Hua ZHANG ◽  
Hai-Dong LU ◽  
Jian-Chao LIU ◽  
...  

2011 ◽  
Vol 37 (8) ◽  
pp. 1432-1440
Author(s):  
Cheng-Yan ZHENG ◽  
Shi-Ming CUI ◽  
Dong WANG ◽  
Zhen-Wen YU ◽  
Yong-Li ZHANG ◽  
...  

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