Gaseous and leaching nitrogen losses from no-tillage and conventional tillage systems following surface application of cattle manure

2008 ◽  
Vol 98 (2) ◽  
pp. 187-199 ◽  
Author(s):  
M.S. Mkhabela ◽  
A. Madani ◽  
R. Gordon ◽  
D. Burton ◽  
D. Cudmore ◽  
...  
2010 ◽  
Vol 45 (12) ◽  
pp. 1331-1341 ◽  
Author(s):  
Homero Bergamaschi ◽  
Genei Antonio Dalmago ◽  
João Ito Bergonci ◽  
Cleusa Adriane Menegassi Bianchi Krüger ◽  
Bruna Maria Machado Heckler ◽  
...  

The objective of this work was to evaluate changes in the photosynthetic photon flux density (PPFD) interception efficiency and PPFD extinction coefficient for maize crop subjected to different soil tillage systems and water availability levels. Crops were subjected to no-tillage and conventional tillage systems combined with full irrigation and non-irrigation treatments. Continuous measurements of transmitted PPFD on the soil surface and incoming PPFD over the canopy were taken throughout the crop cycle. Leaf area index and soil water potential were also measured during the whole period. Considering a mean value over the maize cycle, intercepted PPFD was higher in the conventional tillage than in the no-tillage system. During the initial stages of plants, intercepted PPFD in the conventional tillage was double the PPFD interception in the no-tillage treatment. However, those differences were reduced up to the maximum leaf area index, close to tasseling stage. The lowest interception of PPFD occurred in the conventional tillage during the reproductive period, as leaf senescence progressed. Over the entire crop cycle, the interception of PPFD by the non-irrigated plants was about 20% lower than by the irrigated plants. The no-tillage system reduced the extinction coefficient for PPFD, which may have allowed a higher penetration of solar radiation into the canopy


2011 ◽  
Vol 35 (6) ◽  
pp. 1985-1994 ◽  
Author(s):  
Carina Rosa Álvarez ◽  
Alejandro Oscar Costantini ◽  
Alfredo Bono ◽  
Miguel Ángel Taboada ◽  
Flavio Hernán Gutiérrez Boem ◽  
...  

One of the expected benefits of no-tillage systems is a higher rate of soil C sequestration. However, higher C retention in soil is not always apparent when no-tillage is applied, due e.g., to substantial differences in soil type and initial C content. The main purpose of this study was to evaluate the potential of no-tillage management to increase the stock of total organic C in soils of the Pampas region in Argentina. Forty crop fields under no-tillage and conventional tillage systems and seven undisturbed soils were sampled. Total organic C, total N, their fractions and stratification ratios and the C storage capacity of the soils under different managements were assessed in samples to a depth of 30 cm, in three layers (0-5, 5-15 and 15-30 cm). The differences between the C pools of the undisturbed and cultivated soils were significant (p < 0.05) and most pronounced in the top (0-5 cm) soil layer, with more active C near the soil surface (undisturbed > no-tillage > conventional tillage). Based on the stratification ratio of the labile C pool (0-5/5-15 cm), the untilled were separated from conventionally tilled areas. Much of the variation in potentially mineralizable C was explained by this active C fraction (R² = 0.61) and by total organic C (R² = 0.67). No-till soils did not accumulate more organic C than conventionally tilled soils in the 0-30 cm layer, but there was substantial stratification of total and active C pools at no till sites. If the C stratification ratio is really an indicator of soil quality, then the C storage potential of no-tillage would be greater than in conventional tillage, at least in the surface layers. Particulate organic C and potentially mineralizable C may be useful to evaluate variations in topsoil organic matter.


1988 ◽  
Vol 2 (3) ◽  
pp. 323-326 ◽  
Author(s):  
Kurt D. Thelen ◽  
James J. Kells ◽  
Donald Penner

Field trials were conducted in 1985 and 1986 to determine the effect of incorporation on volatilization of clomazone from soil. Volatilization was detected up to 2 weeks after surface-applied or soil-incorporated treatments of clomazone at 1.1 kg ai/ha. The amount of volatilization detected was greatest following rainfall and varied between years. More clomazone volatilized after surface application than after incorporation, regardless of the climatic conditions present. Clomazone volatilization detected was in the order of no-tillage > minimum tillage > conventional tillage.


Weed Science ◽  
1980 ◽  
Vol 28 (1) ◽  
pp. 101-104 ◽  
Author(s):  
J. J. Kells ◽  
C. E. Rieck ◽  
R. L. Blevins ◽  
W. M. Muir

Field studies and laboratory analyses were conducted to examine factors affecting degradation of14C-atrazine [2-chloro-4-(ethylamine)-6-(isopropylamino)-s-triazine] under field conditions. The effects of these factors on weed control under no-tillage and conventional tillage systems were also examined. The amount of radioactivity which was unextractable in 90% methanol increased with time following treatment with14C-atrazine. The rate of formation of unextractable14C compounds was greater under no-tillage and increased with decreasing pH. After 14 to 18 days, a greater amount of extractable atrazine was present in areas receiving lime. The degradation of atrazine occurred more rapidly when surface pH was less than 5.0 compared with a pH greater than 6.5. The effect of lime on the amount of parent atrazine present in the soil was directly correlated to its effect on soil pH. Extractable atrazine in the soil 45 days after treatment was significantly correlated with weed control with the greatest effect under no-tillage.


Weed Science ◽  
1989 ◽  
Vol 37 (2) ◽  
pp. 233-238 ◽  
Author(s):  
J. Anthony Mills ◽  
William W. Witt

Field experiments were conducted to evaluate the interactions of tillage systems with imazaquin and imazethapyr on weed control and soybean injury and yield. Control of jimsonweed, common cocklebur, ivyleaf morningglory, velvetleaf, and giant foxtail from imazaquin and imazethapyr in conventional tillage was generally equal to or greater than control in no-tillage. However, under limited rainfall, weed control in no-tillage was generally equal to or greater than control in conventional tillage. Reductions in soybean heights due to herbicide treatment were evident in both tillage systems in 1985 and 1986 but not in. Soybean yields were reduced in 1985 from imazaquin at 140, 210, and 250 g/ha and imazethapyr at 105 and 140 g/ha. Yields were not reduced in 1986 and. Imazaquin and imazethapyr appear to provide adequate control of jimsonweed, common cocklebur, ivyleaf morningglory, velvetleaf, and giant foxtail in conventional and no-till systems.


Weed Science ◽  
1999 ◽  
Vol 47 (1) ◽  
pp. 67-73 ◽  
Author(s):  
J. Dorado ◽  
J. P. Del Monte ◽  
C. López-Fando

In a semiarid Mediterranean site in central Spain, field experiments were conducted on a Calcic Haploxeralf (noncalcic brown soil), which had been managed with three crop rotations and two tillage systems (no-tillage and conventional tillage) since 1987. The crop rotations consisted of barley→vetch, barley→sunflower, and a barley monoculture. The study took place in two growing seasons (1992–1994) to assess the effects of management practices on the weed seedbank. During this period, spring weed control was not carried out in winter crops. In the no-tillage system, there was a significant increase in the number of seeds of different weed species: anacyclus, common purslane, corn poppy, knotted hedge-parsley, mouse-ear cress, spring whitlowgrass, tumble pigweed, venus-comb, andVeronica triphyllos.Conversely, the presence of prostrate knotweed and wild radish was highest in plots under conventional tillage. These results suggest large differences in the weed seedbank as a consequence of different soil conditions among tillage systems, but also the necessity of spring weed control when a no-tillage system is used. With regard to crop rotations, the number of seeds of knotted hedge-parsley, mouse-ear cress, and spring whitlowgrass was greater in the plots under the barley→vetch rotation. Common lambsquarters dominated in the plots under the barley→sunflower rotation, whereas venus-comb was the most frequent weed in the barley monoculture. Larger and more diverse weed populations developed in the barley→vetch rotation rather than in the barley→sunflower rotation or the barley monoculture.


2007 ◽  
Vol 95 (1-2) ◽  
pp. 133-148 ◽  
Author(s):  
Katrien Oorts ◽  
Roel Merckx ◽  
Eric Gréhan ◽  
Jérôme Labreuche ◽  
Bernard Nicolardot

HortScience ◽  
1991 ◽  
Vol 26 (12) ◽  
pp. 1475-1478 ◽  
Author(s):  
D.T. Drost ◽  
H.C. Price

Tomatoes (Lycopersicon esculentum Mill.) were grown in conventional tillage (CT), rye (Secale cereale L.) mulch no tillage (RNT), and wheat (Triticum aestivum L.) mulch no tillage (WNT). Either germinated seeds (GS) or raw seeds (RS) were fluid drilled on several dates in 1981 and 1982. Tomato stands in no tillage (NT) generally were equal to or higher than in CT, and stands improved with later plantings in each year. Plant stands were unaffected by GS and RS. Time to 50% emergence (T50) was up to 4 days less in NT than in CT and 2 to 3 days less from GS than RS. Yields with CT were twice as high as those with NT for early planting dates. Yields decreased in CT with successive planting dates to levels equal to NT plantings. Use of GS increased fruit yields as compared to RS, regardless of the planting date.


2004 ◽  
Vol 84 (3) ◽  
pp. 739-747 ◽  
Author(s):  
J. R. Moyer ◽  
J. Nitschelm ◽  
P. Regitnig ◽  
R. E. Blackshaw ◽  
H. C. Huang ◽  
...  

Sugarbeets (Beta vulgaris L.) are grown on intensively tilled-irrigated land in southern Alberta, which is subject to soil erosion by wind. Experiments were conducted on commercial fields near Burdett, AB, to determine the effect of the tillage system and previous crops on sugarbeet production. The previous crops were dry bean (Phaseolus vulgaris L.) or wheat (Triticum aestivium L.) and the tillage systems were conventional (moldboard plow, vibrashank cultivator, harrow, packer), minimum (double disc, self-cleaning harrow, glyphosate) or no tillage (glyphosate). After dry beans, sugarbeet fresh weight and extractable sugar yields were similar with all tillage systems. All of the tillage systems left less than 100 g m-2 of plant residue on the soil surface in the spring following dry beans, which is insufficient to protect the soil from wind erosion. After wheat, sugarbeet yields were similar with minimum and conventional tillage but lower with no tillage. Both minimum and no-tillage systems left sufficient plant residue on the soil surface to protect the soil from erosion (> 200 g m-2). Sugarbeet stand density following wheat was lower with no tillage than conventional or minimum tillage, reflecting poor seed placement and daily maximum soil temperature (5 cm depth) of up to 10°C lower under no tillage than conventional tillage. After wheat, there was a trend toward lower densities of hard-seeded annuals, such as redroot pigweed (Amaranthus retroflexus L.), after no tillage than conventional tillage. Of the cropping systems tested in this study, only the minimum tillage system after wheat provided optimum sugarbeet yield and left enough plant residue to protect the soil from wind erosion. Key words: Crop rotation, bean, wheat, sugarbeet, no-tillage


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