Cropping system history and crop rotation phase drive the abundance of soil denitrification genes nirK, nirS and nosZ in conventional and organic grain agroecosystems

2019 ◽  
Vol 273 ◽  
pp. 95-106 ◽  
Author(s):  
Jude E. Maul ◽  
Michel A. Cavigelli ◽  
Bryan Vinyard ◽  
Jeffrey S. Buyer
Author(s):  
V. А. Shchedrin

In OOO “Dubovitskoe” which was organized in 2006 as investment project of the AO “Shchelkovo Agrokhim” for 2010 – 2012 three advanced crop rotations have been developed. Before their introduction the grain crops fraction in the cropping system was 62%, then it fell to 49%. At the same time the portion of raw crops increased from 15 to 20%, legumes from 6 to 8%, others (buckwheat, grain maize, etc.) - up to 23%. As of 2017, the crops of leguminous crops have increased noteworthily. There are two predominant soil types here heavy clay loam podzolized chernozem (6615 ha) and grey forest soil (856 ha). Weighted average indicators (as of 2017): humus content in the soils of arable land is 5, 34%; acidity pH is 4.92; labile phosphorus - 111.8 mg / kg soil; exchange potassium - 144 mg / kg soil. The coefficient of the soil fertility in the enterprise (weighted average) is 0.66. This means that maintaining and increasing the soil fertility for arable land of the enterprise is critical task. As a result of the research, it has been established that the technologies introduced in the crop vegetation management (CVS) in the crop rotation conditions ensure high productivity of cultivated crops and stability of humus content in soils as an energy basis and a guarantor of increasing fertility. The indicators of the labile phosphorus Р205 and exchange potassium К20 in the soils depending on the crop rotation vary from a certain decrease to expressed steady growth. Therefore it is necessary to specify seeding rates based on actual data. Sustainable soil acidification in the crop rotations under crop cultivation in OOO “Dubovitskoe” it is the result of the acid feterlizers high rates application, during studying period did not carried out required agromelioration with calcium contenting elements.


2001 ◽  
Vol 81 (4) ◽  
pp. 805-813 ◽  
Author(s):  
R. E. Blackshaw ◽  
F. J. Larney ◽  
C. W. Lindwall ◽  
P. R. Watson ◽  
D. A. Derksen

Development of improved weed manage ment systems requires more knowledge on how various weed species respond to changing agronomic practices. A long-term study was conducted to determine weed population responses to various tillage intensities and crop rotations in a winter wheat (Triticum aestivum L.) dominated cropping system. Weed density and species composition differed with tillage, rotation, year, and date of sampling within years. Weed community dynamics were most affected by year-to-year differences in environmental conditions, followed by crop rotation, and then tillage intensity. Russian thistle (Salsola iberica Sennen & Pau) and kochia [Kochia scoparia (L.) Schrad.] densities increased in years of low rainfall and above average temperatures. Winter annual weeds such as downy brome (Bromus tectorum L.) and flixweed [Descurainia sophia (L.) Webb ex Prantl], as well as the perennial weed dandelion (Taraxacum officinale Weber in Wiggers), increased in years where higher than average rainfall was received in fall or early spring. Continuous winter wheat facilitated a dense downy brome infestation to develop over time. Trifluralin is not efficacious on stinkweed (Thlaspi arvense L.) or Canada thistle [Cirsium arvense (L.) Scop.] and its use in canola resulted in an increase in these species in a winter wheat-canola rotation. Total weed densities were often greater in zero tillage than in either minimum or conventional tillage. Russian thistle, downy brome, kochia, and redroot pigweed (Amaranthus retroflexus L.) were associated with zero tillage while wild buckwheat (Polygonum convolvulus L.), lamb’s-quarters (Chenopodium album L.), flixweed, and wild mustard (Sinapis arvensis L.) were associated with conventional tillage. Perennials such as dandelion and perennial sowthistle (Sonchus arvensis L.) were associated with zero tillage but Canada thistle was associated with conventional tillage. Information will be utilized to implement more effective weed management programs in winter wheat production systems. Key words: Conservation tillage, fallow, multivariate analyses, weed populations, weed shifts, zero tillage


2021 ◽  
Vol 3 ◽  
Author(s):  
Giovanni Antonio Puliga ◽  
Jan Thiele ◽  
Hauke Ahnemann ◽  
Jens Dauber

In agroecosystems, crop diversification plays a fundamental role in maintaining and regenerating biodiversity and ecosystem services, such as natural pest control. Temporal diversification of cropping systems can affect the presence and activity of natural enemies by providing alternative hosts and prey, food, and refuges for overwintering. However, we still lack studies on the effects of temporal diversification on generalist predators and their biocontrol potential conducted at field scale in commercial agricultural settings. Here, we measured proxies of ecosystem functions related with biological pest control in 29 commercial agricultural fields characterized by cereal-based cropping system in Lower-Saxony, northern Germany. The fields differed in the number of crops and cover crops cultivated during the previous 12 years. Using the Rapid Ecosystem Function Assessment approach, we measured invertebrate predation, seed predation and activity density of generalist predators. We aimed at testing whether the differences in the crop rotations from the previous years would affect activity of predators and their predation rates in the current growing season. We found that the length of the crop rotation had neutral effects on the proxies measured. Furthermore, predation rates were generally lower if the rotation comprised a higher number of cover crops compared to rotation with less cover crops. The activity density of respective taxa of predatory arthropods responded differently to the number of cover crops in the crop rotation. Our results suggest that temporal crop diversity may not benefit the activity and efficiency of generalist predators when diversification strategies involve crops of very similar functional traits. Adding different resources and traits to the agroecosystems through a wider range of cultivated crops and the integration of semi-natural habitats are aspects that need to be considered when developing more diverse cropping systems aiming to provide a more efficient natural pest control.


2008 ◽  
Vol 311 (1-2) ◽  
pp. 29-38 ◽  
Author(s):  
S. G. K. Adiku ◽  
S. Narh ◽  
J. W. Jones ◽  
K. B. Laryea ◽  
G. N. Dowuona

2008 ◽  
Vol 54 (No. 9) ◽  
pp. 395-402 ◽  
Author(s):  
M. Váňová ◽  
K. Klem ◽  
P. Míša ◽  
P. Matušinsky ◽  
J. Hajšlová ◽  
...  

Nine cultivars of winter wheat were compared in organic and conventional crop rotation systems. Bread-making quality was evaluated using three parameters [thousand-kernel weight (TKW) in g, volume weight in g/l, protein content in %]. Grain yield, TKW and protein content of winter wheat in organic cropping system were significantly lower as compared to any intensity in conventional cropping system. However, clover as a preceding crop to winter wheat in organic crop rotation ensured a sufficient amount of nitrogen for grain yield, which was 6.72 t/ha on average of the three years. The requirement of the Czech national standard for bread wheat minimum value of protein content (11.5%) was met in conventional crop rotation in all cases. Average value of protein content in organic crop rotation met this limit too, but it was below the required value in two cases. The required value (760 g/l) of volume weight was met in majority of cases in organic crop rotation. The following species of the genus <I>Fusarium were</I> found: <I>F. culmorum, F. graminearum, F. poae</I> and <I>F. avenaceum</I>. All samples were screened for the content of deoxynivalenol (DON). There was no significant difference in the DON content between winter wheat grain from organic crop rotation and conventional crop rotation at high intensity.


2005 ◽  
Vol 20 (2) ◽  
pp. 91-100 ◽  
Author(s):  
A. Schoofs ◽  
M.H. Entz ◽  
R.C. Van Acker ◽  
J.R. Thiessen Martens ◽  
D.A. Derksen

AbstractPesticide Free Production (PFP) is a pesticide reduction system that removes in-crop pesticide use on a yearly basis. A long-term study was established in 2000 to investigate the effect of crop rotation and frequency of inclusion on the success of PFP, as well as the effect of PFP on subsequent crops in the rotation. The crop rotations being compared were linola–oat–canola–wheat and linola–oat–alfalfa–alfalfa. PFP occurred either once in the rotation (oat) or twice (linola–oat). Weed density and yield were measured in the crops that followed PFP. Oat was a more successful PFP crop than linola because it was better able to compete with weeds. Furthermore, PFP oat had a higher weed density when it followed PFP linola, but this did not influence PFP oat yield. Under the conditions of this study, PFP linola was more successful in the annual crop rotation. Inclusion of alfalfa hay crops in the crop rotation was not effective in lowering weed pressure and, in fact, may have contributed to an increase in weed density. It is concluded that weed species present influenced the effectiveness of alfalfa in facilitating PFP, because major weeds in the study are not effectively controlled by alfalfa. PFP did not have a negative effect on following crops in the rotation (i.e. canola–wheat or alfalfa), regardless of whether one or two consecutive years of PFP occurred in the rotation. No additional herbicide was necessary for weed control in the crops that followed PFP; however, alfalfa hay was weedier for the first year following PFP. This study indicates that PFP is a viable way to reduce herbicide use in a cropping system and that attention needs to be paid to PFP crop selection and crop rotation, particularly when the PFP crop is less competitive with weeds.


Author(s):  
R. Sammauria ◽  
O.P. Meena ◽  
M.R. Yadav ◽  
A.K. Gupta ◽  
H.L. Yadav ◽  
...  

Continuous adoption of Pearl millet-Wheat cropping system led to reduction in productivity which put a serious threat to its sustainability in semi-arid eastern plain zone of Rajasthan, India. Crop diversification with wider choice with a variety of crops is being promoted as an alternative to profit maximization with enhanced soil fertility status. Therefore, a long term experiment was initiated to evaluate the production potential, sustainability, resource-use efficiency and economics of nine Pearl millet based cropping systems. Result revealed that system productivity in terms of pearl millet equivalent yield (PMEY) was highest (30488 kg ha-1) with groundnut-wheat-cluster bean-onion crop rotation. Moreover, groundnut-wheat-cluster bean-onion recorded the highest SYI and land use efficiency (0.65 and 73.97%) followed by pearl millet-wheat-cluster bean-barley sequence (0.63 and 65.75%). The groundnut-wheat-cluster bean-onion also generated highest number of man days/ha/year (405). The highest values of organic carbon were found under green gram-mustard-pearl millet-lentil and cluster bean-pea-pearl millet-lentil. The maximum value of available P was recorded with cluster bean-mustard-green gram-garden cress followed by the groundnut-wheat-cluster bean-onion sequence. Available K decreased significantly from their initial values in all the cropping systems except groundnut-wheat-cluster bean-onion crop rotation. Among the various systems, groundnut-wheat-cluster bean-onion realized the highest net returns ( 213000 ha-1), followed by pearl millet-wheat-cluster bean-barley ( 163254 ha-1). Overall, it can be concluded that under the semi-arid agro climatic conditions of Rajasthan, groundnut-wheat-cluster bean-onion, followed by pearl millet-wheat-cluster bean-barley, were more productive, sustainable, resource use efficient and remunerative than other cropping systems.


1991 ◽  
Vol 42 (3) ◽  
pp. 391 ◽  
Author(s):  
DR Coventry ◽  
WJ Slattery

Soil pH decline and net acidification inputs were determined for a long-term crop rotation experiment at Rutherglen in north-eastern Victoria. The rotations utilized were continuous wheat (WW), a 1 : 1 wheat-lupin sequence (WL) and continuous lupins (LL), and each rotation was cropped from 1975-1989. The soil at the site had an initial pH (0.01 mol/LCaCl2) of 6.0 (0-10 cm depth), sandy loam texture, and had a past use of grape vines and then lucerne pasture. The soil pH (0-10 cm) declined for each rotation with time (1977/78-1988/89), decreasing by about 0.8 units for WW and further decreasing with the inclusion of lupin in the rotation. Compared with the WW soil, the WL soil pH was 0.7 and 0.4 units lower at 5-10 cm and 10-15 cm depth and the LL soil pH was 1.0 and 0.8 units lower at 5-10 and 10-15 cm depth. There was no difference in pH between WW and WL below 20 cm depth, but the LL soil had a significantly lower pH to 40 cm depth. Acidification rates were calculated for the period of cropping and for the 3 rotations, with rates of 3.22, 4.11 and 5.26 kmols H+/ha.yr as net acid input for WW, WL and LL rotations. These values represent a rapid rate of soil acidification. The removal of alkalinity in grain accounted for between 15-21% of the overall calculated acidification rate for the 3 rotations. Therefore, it is likely in this cropping system that the acidification largely results from progressive nitrate leaching.


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