Rainfed crop energy balance of different farming systems and crop rotations in a semi-arid environment: Results of a long-term trial

2011 ◽  
Vol 114 (1) ◽  
pp. 18-27 ◽  
Author(s):  
M.M. Moreno ◽  
C. Lacasta ◽  
R. Meco ◽  
C. Moreno
Author(s):  
Cornelia CIOBANU ◽  
Cornel DOMUŢA ◽  
Gheorghe CIOBANU ◽  
Maria ŞANDOR ◽  
Alina Dora SAMUEL ◽  
...  

The paper based on the researches carried out during 2005 – 2008 in the long term trial placed in 1990 on the preluvosoil from Oradea. The monoculture of maize, maize – wheat and maize – soybean – wheat crop rotations were studied in unirrigated and irrigated conditions. The crop rotatin of six years (oat + clover – clover – maize – wheat – maize - sunflower) was studied in unirrigated conditions. The researches emphasized that the monoculture is the most responsible for the pest multiplication. In maize monoculture the larvae number on the roots was ranged between 4.91-8.23 and root attack degree in IOWA scale (with marks from 1 to 6 in which maximum attack is 6), had values between 3.84 and 5.62 and the frequent of attacked plants with the symptom “goose neck” ranged between 16,4% and 31.2% and larval aggressiveness being higher in the case of favorable soil moisture in irrigated condition. The maize rotation with other plants interrupts the biologic pest cycle. The results obtained emphasize that later maize sowing alongside by the utilizing of lower plant thickness level contribute to prevention of pest multiplication, while earlier sowing at high thickness favor the larvae developing.


Author(s):  
Andris Lejiņš ◽  
Biruta Lejiņa

Buckwheat research has been carried out within the long-term crop rotation stationary that was established in 1969 as a part of the Research institute of Agriculture. Buckwheat proportion within the partcular crop rotations went up to 22%. The highest buckwheat yields were obtained from the buckwheat variants that where cultivated after winter rye, and within the buckwheat monoculture experimental plots. A considerable yield decrease was observed when cultivating buckwheat after potatoes. Weeds in the buckwheat sowing were effectively brought under control by the herbicide Butisane 400 (1.5 l ha-1), applied immediately after sowing and Betanal AM 2.5 l ha-1 after seedling in 2-3 leaves stage.


2012 ◽  
Vol 16 (3) ◽  
pp. 893-910
Author(s):  
X. Xiao ◽  
H. C. Zuo ◽  
Q. D. Yang ◽  
S. J. Wang ◽  
L. J. Wang ◽  
...  

Abstract. The energy observed in the surface layer, when using eddy-covariance techniques to measure turbulent fluxes, is not balanced. Important progress has been made in recent years in identifying potential reasons for this lack of closure in the energy balance, but the problem is not yet resolved. In this paper, long-term data that include output of tower, radiation, surface turbulence flux and soil measurement collected from September 2006 to August 2010 in the Semi-Arid Climate Change and Environment Observatory, Lanzhou University, in the semi-arid Loess Plateau of Northwest China, were analysed, focusing on the seasonal characteristics of the surface energy and the factors that have impact on the energy balance closure (EBC). The analysis shows that (1) the long-term observations are successful; the interaction between the land and the atmosphere in semi-arid climates can be represented by the turbulent transport of energy. In addition, even though the residual is obvious, this suggests that the factors that impact the EBC are stable, and their seasonal variations are identical. The analysis also shows that (2) four factors have obvious impact on the EBC: the diverse schemes for surface soil heat flux, the flux contribution from the target source area, the low-frequency part of the turbulence spectra, and the strength of atmospheric turbulence motion. The impact of these four factors on the EBC are similar in all seasons. Lastly, the results indicate that (3) atmospheric turbulence intensity is a very important factor in terms of its impact on the EBC. The relative turbulence intensity, RIw, characterises the strength of atmospheric turbulence motion, and is found to exert a noticeable impact on the EBC; in all seasons, the EBC is increased when the relative turbulence intensity is enlarged.


2019 ◽  
Vol 157 (6) ◽  
pp. 504-514
Author(s):  
T. Muoni ◽  
B. Mhlanga ◽  
J. Forkman ◽  
M. Sitali ◽  
C. Thierfelder

AbstractMacro-organisms contribute significantly to soil fertility improvement. The influence of conservation agriculture (CA) in southern Africa on their populations has not yet been fully understood. Thus, the objective of the current study was to evaluate the effects of CA and conventional tillage on below ground biological activity in a CA long-term trial in Monze, Zambia from 2011 to 2013. The study had ten treatments which differed by tillage systems (conventional ploughing, planting basins and direct seeding) and crop diversification intensity (sole cropping, 2- or 3-year crop rotations) involving maize, cotton and sunn hemp. These factors were combined to create rotation-tillage (RotTill) treatments. Sampling of macrofauna was done once per year using a metal frame measuring 0.25 m2, hand-sorted to 30-cm depth. RotTill treatments had a significant effect on earthworms (Lumbricus terrestris), termites (Coptotermes formosanus), dung beetles (Scarabaeus viettei) and centipedes (Lithobius forficatus). Earthworms and termites were more abundant in CA treatments than in conventionally ploughed (CP) treatments. Biota diversity was generally higher in CA treatments than in CP controls. Conventional mouldboard ploughing generally reduced macrofauna, thus affecting biological soil fertility and the beneficial effect of the interactions of these organisms with the soil. CA treatments had the highest maize grain yields throughout the study period. Based on the results, reduced tillage systems and crop rotations increase biological activity shown by increased densities of termites and earthworms.


2016 ◽  
Vol 27 (3) ◽  
pp. 612-619 ◽  
Author(s):  
Agata Novara ◽  
Ignazio Poma ◽  
Mauro Sarno ◽  
Giacomo Venezia ◽  
Luciano Gristina

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