Expansion of no-tillage practice in conservation agriculture in Brazil

AbstractConservation agriculture has been promoted to sustainably intensify food production in smallholder farming systems in southern Africa. However, farmers have rarely fully implemented all its components, resulting in different combinations of no-tillage, crop rotation, and permanent soil cover being practiced, thus resulting in variable yield responses depending on climatic and soil conditions. Therefore, it is crucial to assess the effect of conservation agriculture components on yield stability. We hypothesized that the use of all three conservation agriculture components would perform the best, resulting in more stable production in all environments. We evaluated at, eight trial locations across southern Africa, how partial and full implementation of these components affected crop yield and yield stability compared with conventional tillage alone or combined with mulching and/or crop rotation. Grain yield and shoot biomass of maize and cowpea were recorded along with precipitation for 2 to 5 years. Across different environments, the addition of crop rotation and mulch to no-tillage increased maize grain by 6%, and the same practices added to conventional tillage led to 13% yield increase. Conversely, adding only mulch or crop rotation to no-tillage or conventional tillage led to lower or equal maize yield. Stability analyses based on Shukla’s index showed for the first time that the most stable systems are those in which mulch is added without crop rotation. Moreover, the highest yielding systems were the least stable. Finally, additive main effects and multiplicative interaction analysis allowed clarifying that mulch added to no-tillage gives stable yields on sandy soil with high rainfall. Similarly, mulch added to conventional tillage gives stable yield on sandy soil, but under low rainfall. This is the first study that highlighted the crucial role of mulch to enhance the stability and resilience of cropping systems in southern Africa, supporting their adaptability to climate change.

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Impact of Weed Control by Hand Tools on Soil Erosion under a No-Tillage System Cultivation

Agronomy ◽

10.3390/agronomy11050974 ◽

2021 ◽

Vol 11 (5) ◽

pp. 974

Author(s):

Rafael Blanco-Sepúlveda ◽

Amilcar Aguilar-Carrillo ◽

Francisco Lima

Keyword(s):

Soil Erosion ◽

Weed Control ◽

Soil Cover ◽

Soil Surface ◽

Conservation Agriculture ◽

Soil Disturbance ◽

No Tillage ◽

Tropical Mountains ◽

Litter Cover ◽

Vegetal Cover

In conservation agriculture, the no-tillage cultivation system and the retention of permanent vegetal cover are crucial to the control of soil erosion by water. This paper analyses the cultivation of maize under no-tillage, with particular reference to the effect produced on soil erosion when weed control is performed by a hand tool (machete), which disturbs the surface of the soil, and to the behavior of the soil cover in these circumstances. The study area is located in the humid tropical mountains of northern Nicaragua (Peñas Blancas Massif Nature Reserve). The results obtained show that 59.2% of the soil surface was affected by appreciable levels of sheet and splash erosion, although the vegetal cover of the soil was relatively high (with average weed and litter cover of 33.9% and 33.8%, respectively). The use of machetes for weed control provoked considerable soil disturbance, which explained the high rates of erosion observed. Moreover, this form of soil management disturbs the litter layer, making it less effective in preventing erosion. The litter remains loose on the soil surface, and so an increase in soil cover does not achieve a proportionate reduction in the area affected by erosion; thus, even with 80–100% weed and litter cover, 42% of the cultivated area continued to present soil erosion.

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Effect of conservation agriculture practices on the resilience of Mediterranean soils to the predicted seasonal drought events

10.5194/egusphere-egu21-7994 ◽

2021 ◽

Author(s):

Laura Morales ◽

María T Domínguez ◽

Mª Belén Herrador ◽

Engracia Madejón ◽

Elena Fernández-Boy

Keyword(s):

Land Management ◽

Management Practices ◽

Conservation Agriculture ◽

No Tillage ◽

Soil Dna ◽

Soil Microbial ◽

Respiration Rates ◽

Soil Functioning ◽

Soil Resilience

<p>How climate change will affect soil functioning is a major concern, especially in Mediterranean agrosystems, where, according to climate change projections, the occurrence of extreme temperatures and drought events will be increased. The main objective of our experiment was to evaluate the effect of land management (tillage system) on soil resilience against a simulated dry-rewetting cycle. Soil samples were collected from an in-situ field experiment established in 2008 in the Guadalquivir Valley, where conservation agriculture practices have been tested. Three different land management practices under a typical Mediterranean wheat-legume rotation system were compared: 1) traditional tillage (TT), 2) minimum tillage (MT) and 3) no-tillage (NT). Following our hypothesis, conservation agriculture practices (reduced tillage and no-tillage) may allow a more mature soil microbial community by reducing soil perturbation, and this would result in higher resistance of soil functioning against drought periods. Soil enzyme activities (&#946;-glucosidase, phosphatase, acetylglucosaminidase, aminopeptidase, and dehydrogenase activities), microbial functional diversity (Microresp method), and soil DNA concentration (as an index of microbial biomass) were analyzed in a base-line sampling. Afterwards, a dry-rewetting cycle was simulated under controlled conditions. 8 subsamples of 50g from each soil sample were hydrated to reach 70% of each soil water holding capacity (WHC) and kept in those conditions for a pre-incubation period of 15 days. After this period, half of the replicates were let dry for 12 days (drought), while the others were maintained at 70% WFC (controls). Finally, all replicates were rehydrated again to the initial water content during a 14 days rewetting period. During this cycle, soil respiration rates were periodically measured to study the evolution of soil microbial activity. Our results showed that initial respiration rates were slightly higher in MT compared to NT (p<0.1), likely due to higher organic C and N content in the MT soils. Drought extremely reduced respiration rates in the three treatments, but the results did not show a clear pattern among treatments. During the rewetting period, respiration rates were significantly higher in drought samples in comparison with the controls, while no significant differences were found for the land management treatments. Besides, land management practices did not have a significant effect on soil DNA concentration, functional diversity of the microbial community, or enzyme activities. To conclude, the absence of a clear effect of land management practices on soil resilience to drought may be due to the experimental conditions. An in-situ experiment will allow us to determine if tillage reduction enhances soil resilience to moisture stress.</p>

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Pesticide regulation in the European Union and the glyphosate controversy

Weed Science ◽

10.1017/wsc.2019.59 ◽

2020 ◽

Vol 68 (3) ◽

pp. 214-222 ◽

Cited By ~ 6

Author(s):

Per Kudsk ◽

Solvejg Kopp Mathiassen

Keyword(s):

European Union ◽

Cover Crops ◽

Conservation Agriculture ◽

Farm Income ◽

No Tillage ◽

The European Union ◽

Public Attention ◽

Pesticide Regulation ◽

The Impact ◽

The Eu

AbstractThe glyphosate controversy before the renewal of the authorization of glyphosate in the European Union (EU) once again turned the spotlight on pesticide regulation in the EU. In the EU, pesticides are attracting more public attention than in other parts of the world, and many nongovernmental organizations specifically target pesticide regulation, trying to influence politicians and other decision makers. Following an overview of the EU pesticide legislation and the impact hitherto on EU agriculture, this paper outlines the glyphosate controversy and presents the outcome of desk studies conducted in Germany, the United Kingdom, France, and Sweden on the potential effects of a glyphosate ban on agricultural productivity and farm income. All studies concluded that the loss of income depends very much on farm type and cropping practice, but they all reached the conclusion that particularly no-tillage farming/conservation agriculture will be facing severe problems without glyphosate to control weeds and terminate cover crops. No-tillage/conservation agriculture is viewed as an effective strategy to prevent soil erosion and loss of nutrients, which could become larger problems without glyphosate. Other issues highlighted in the studies were the impact on resistance management, as glyphosate is largely seen as a “herbicide-resistance breaker.” Without glyphosate, fundamental changes in farming practices in the EU are required, and it is hard to imagine that they will come without a cost, at least in the short term.

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Bioactive Properties of Fruits and Leafy Vegetables Managed with Integrated, Organic, and Organic No-Tillage Practices in the Mediterranean Area: A Two-Year Rotation Experiment

Agronomy ◽

10.3390/agronomy10060841 ◽

2020 ◽

Vol 10 (6) ◽

pp. 841 ◽

Cited By ~ 2

Author(s):

Costanza Ceccanti ◽

Marco Landi ◽

Daniele Antichi ◽

Lucia Guidi ◽

Luigi Manfrini ◽

...

Keyword(s):

Bioactive Compounds ◽

Environmental Sustainability ◽

Management Practices ◽

Cropping Systems ◽

Cropping System ◽

Conservation Agriculture ◽

Leafy Vegetables ◽

No Tillage ◽

Cash Crops ◽

Starting Point

The sustainability of current farming systems has been questioned in the last decades, especially in terms of the environmental impact and mitigation of global warming. Also, the organic sector, which is supposed to impact less on the environment than other more intensive systems, is looking for innovative solutions to improve its environmental sustainability. Promisingly, the integration of organic management practices with conservation agriculture techniques may help to increase environmental sustainability of food production. However, little is known about the possible impact of conservation agriculture on the content of bioactive compounds in cash crops. For this reason, a two-year rotation experiment used 7 cash crops (4 leafy vegetables and 3 fruit crops) to compare integrated (INT), organic farming (ORG), and organic no-tillage (ORG+) systems to evaluate the possible influence of cropping systems on the nutritional/nutraceutical values of the obtained fruits and leafy vegetables. The results pointed out specific responses based on the species as well as the year of cultivation. However, cultivation with the ORG+ cropping system resulted in effective obtainment of fruits and vegetables with higher levels of bioactive compounds in several cases (11 out 16 observations). The ORG+ cropping system results are particularly promising for leafy vegetable cultivation, especially when ORG+ is carried out on a multi-year basis. Aware that the obtained data should be consolidated with longer-term experiments, we conclude that this dataset may represent a good starting point to support conservation agriculture systems as a possible sustainable strategy to obtain products with higher levels of bioactive compounds.

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Yield and Quality Performance of Traditional and Improved Bread and Durum Wheat Varieties under Two Conservation Tillage Systems

Sustainability ◽

10.3390/su11174522 ◽

2019 ◽

Vol 11 (17) ◽

pp. 4522 ◽

Cited By ~ 2

Author(s):

Magdalena Ruiz ◽

Encarna Zambrana ◽

Rosario Fite ◽

Aida Sole ◽

Jose Luis Tenorio ◽

...

Keyword(s):

Durum Wheat ◽

Management Practices ◽

Conservation Tillage ◽

Morphological Characteristics ◽

Conservation Agriculture ◽

Conventional Tillage ◽

Quality Parameters ◽

Climatic Conditions ◽

No Tillage ◽

Wheat Varieties

The increasing spread of conservation agriculture demands that the next generation of wheat varieties includes cultivars capable of maintaining satisfactory yields with lower inputs and under uncertain climate scenarios. On the basis of the genetic gains achieved during decades of selection oriented to yield improvements under conventional crop management, it is important that novel breeding targets are defined and addressed. Grain yield, yield-related traits, and phenological and morphological characteristics, as well as functional quality parameters have been analyzed for six varieties each of bread and durum wheat, under minimum tillage and no-tillage. During the three-year experiment, the climatic conditions at the field trial site were characterized by low rainfall, although different degrees of aridity—from moderate to severe—were experienced. Differences were found between these two soil management practices in regard to the varieties’ yield stability. A positive influence of no-tillage on traits related to grain and biomass yield was also evidenced, and some traits among the examined seemed involved in varietal adaptation to a particular non-conventional tillage system. The study also confirmed some breeding targets for improved performance of wheat genotypes in conservation agroecosystems. These traits were represented in the small set of traditional varieties analysed.

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Production of summer crops in northern New South Wales. I. Effects of tillage and double cropping on growth, grain and N yields of six crops

Australian Journal of Agricultural Research ◽

10.1071/ar9920105 ◽

1992 ◽

Vol 43 (1) ◽

pp. 105 ◽

Cited By ~ 19

Author(s):

DF Herridge ◽

JF Holland

Keyword(s):

N2 Fixation ◽

Field Experiments ◽

New South ◽

New South Wales ◽

Growth Yield ◽

No Tillage ◽

Tillage Practice ◽

Grain Yields ◽

Double Cropping ◽

South Wales

The effects of tillage practice and double cropping on growth, yield and N economies of summer crops were examined in field experiments near Tamworth, northern New South Wales. Sorghum, sunflower, soybean, mungbean, cowpea and pigeon pea were sown into alkaline, black earth soils which contained either high (Site A, sown January 1983), moderate (Site B, sown December 1983), or low concentrations of nitrate (Site C, sown December 1984). During the previous winters, the land had been sown to wheat (double crop) or fallowed using cultivation or no-tillage practices. At Sites A and B, dry matter yields, averaged over all crops, were increased by 34 and 14% under no-tillage. Average increases in grain yields at the two sites were 22 and 11%. At Site C, tillage practice did not affect yields. Soybean showed the greatest responses to no-tillage. Increases in grain yields were 46, 15 and 18% for Sites A, B and C respectively. The least responsive legume was mungbean. Yields of sorghum were increased by 41% at Site A; responses at Sites B and C ranged between a 9% decrease and a 7% increase. With double cropping, grain yields were, on average, 18 (Site A), 81 (Site B) and 72% (Site C) of the yields in the cultivated (fallow) plots. However, when comparisons were made for the 12 month periods, i.e. wheat and summer crops v. fallow and summer crops, production was more than doubled at Site B and tripled at Site C, compared with the cultivated fallow. Significant in the responses to double cropping were the 192 (Site B) and 230 mm rainfalls (Site C) during November and December that replenished the soil profile with water to a depth of >0.75 m. Assessments of soybean N2 fixation using the ureide method indicated large effects of site and season on the proportion of plant N derived from N2 fixation (range, 0-0.83), on the amount of N2 fixed (range, 0-233 kg N ha-1) and on the N balance as a result of the cropping (range, -69 to +45 kg N ha-1).

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