Sustaining crop productivity while reducing environmental nitrogen losses in the subtropical wheat-maize cropping systems: A comprehensive case study of nitrogen cycling and balance

AbstractPromoting crop diversification in European agriculture is a key pillar of the agroecological transition. Diversifying crops generally enhances crop productivity, quality, soil health and fertility, and resilience to pests and diseases and reduces environmental stresses. Moreover, crop diversification provides an alternative means of enhancing farmers’ income. Camelina (Camelina sativa (L.) Crantz) reemerged in the background of European agriculture approximately three decades ago, when the first studies on this ancient native oilseed species were published. Since then, a considerable number of studies on this species has been carried out in Europe. The main interest in camelina is related to its (1) broad environmental adaptability, (2) low-input requirements, (3) resistance to multiple pests and diseases, and (4) multiple uses in food, feed, and biobased applications. The present article is a comprehensive and critical review of research carried out in Europe (compared with the rest of the world) on camelina in the last three decades, including genetics and breeding, agronomy and cropping systems, and end-uses, with the aim of making camelina an attractive new candidate crop for European farming systems. Furthermore, a critical evaluation of what is still missing to scale camelina up from a promising oilseed to a commonly cultivated crop in Europe is also provided (1) to motivate scientists to promote their studies and (2) to show farmers and end-users the real potential of this interesting species.

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The Pitfalls of Relating Weeds, Herbicide Use, and Crop Yield: Don't Fall Into the Trap! A Critical Review

Frontiers in Agronomy ◽

10.3389/fagro.2020.615470 ◽

2020 ◽

Vol 2 ◽

Author(s):

Nathalie Colbach ◽

Sandrine Petit ◽

Bruno Chauvel ◽

Violaine Deytieux ◽

Martin Lechenet ◽

...

Keyword(s):

Crop Yield ◽

Weed Management ◽

Crop Production ◽

Yield Loss ◽

Crop Yields ◽

Cropping Systems ◽

Crop Productivity ◽

Arable Farming ◽

Herbicide Use ◽

The Impact

The growing recognition of the environmental and health issues associated to pesticide use requires to investigate how to manage weeds with less or no herbicides in arable farming while maintaining crop productivity. The questions of weed harmfulness, herbicide efficacy, the effects of herbicide use on crop yields, and the effect of reducing herbicides on crop production have been addressed over the years but results and interpretations often appear contradictory. In this paper, we critically analyze studies that have focused on the herbicide use, weeds and crop yield nexus. We identified many inconsistencies in the published results and demonstrate that these often stem from differences in the methodologies used and in the choice of the conceptual model that links the three items. Our main findings are: (1) although our review confirms that herbicide reduction increases weed infestation if not compensated by other cultural techniques, there are many shortcomings in the different methods used to assess the impact of weeds on crop production; (2) Reducing herbicide use rarely results in increased crop yield loss due to weeds if farmers compensate low herbicide use by other efficient cultural practices; (3) There is a need for comprehensive studies describing the effect of cropping systems on crop production that explicitly include weeds and disentangle the impact of herbicides from the effect of other practices on weeds and on crop production. We propose a framework that presents all the links and feed-backs that must be considered when analyzing the herbicide-weed-crop yield nexus. We then provide a number of methodological recommendations for future studies. We conclude that, since weeds are causing yield loss, reduced herbicide use and maintained crop productivity necessarily requires a redesign of cropping systems. These new systems should include both agronomic and biodiversity-based levers acting in concert to deliver sustainable weed management.

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Effects of conservation agriculture on productivity and Economics of maize-wheat based cropping systems in midwestern Nepal

SAARC Journal of Agriculture ◽

10.3329/sja.v17i1.42761 ◽

2019 ◽

Vol 17 (1) ◽

pp. 49-63

Author(s):

K Pariyar ◽

A Chaudhary ◽

P Sapkota ◽

S Sharma ◽

CB Rana ◽

...

Keyword(s):

Grain Yield ◽

Cropping Systems ◽

Cropping System ◽

Conservation Agriculture ◽

Crop Productivity ◽

Conventional Tillage ◽

Net Income ◽

Zero Tillage ◽

Higher Plant ◽

Equivalent Yield

The effects of two tillage methods (zero tillage and conventional tillage), two residue managements (residue kept and residue removed) and two levels of cropping system (maize + soybean and sole maize) were studied over 3 years (2015-2017) at Dailekh district of Nepal. Arun-2 and Puja were the varieties of maize and soybean used respectively, followed by winter wheat. The results revealed that the maize + soybean system had significantly higher plant population and ear population (34.83 thousands ha-1 and 34.35 thousands ha-1, respectively), grains per row (37.1), ear length (16.6 cm) and 20.5% higher grain yield as compared to sole maize. The highest maize equivalent yield (7.92 t ha-1) was recorded in maize + soybean as compared to the lower grain yield equivalent (7.06 t ha-1) in sole maize. Zero tillage accounted relatively higher benefits (high net income and B:C ratio) as compared to conventional tillage. The residue kept plot resulted significantly higher B:C ratio (2.41) than the residue removed (2.11) and the maize + soybean recorded 82.5% greater B:C ratio compared to sole maize. Net annual income was significantly higher in zero tillage, residue kept and maize + soybean system (NRs. 223072.00, 222958.00 and 269016.00 ha-1 respectively). Such combinations are recommended for Dailekh district of Nepal to have profitable crop productivity. SAARC J. Agri., 17(1): 49-63 (2019)

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