Functionally diverse flax-based rotations improve wild oat (Avena fatua) and cleavers (Galium spurium) management

Wild oat (Avena fatua L.) and false cleavers (Galium spurium) are currently a challenge to manage in less competitive crops such as flax (Linum usitatissimum L.). Increasing the functional diversity in crop rotations can be an option to improve weed management. Nonetheless, this strategy is not tested in flax in Western Canada. A 5-yr (2015-2019) crop rotation study was carried at three locations in western Canada to determine the effect of diverse flax-based crop rotations with differences in crop species, crop life cycles, harvesting time and reduced herbicides on managing A. fatua and G. spurium. The perennial rotation (flax-alfalfa (Medicago sativa L.)-alfalfa-alfalfa-flax) under reduced herbicide use was found to be the most consistent cropping system, providing similar A. fatua and G. spurium control to the conventional annual flax crop rotation[flax-barley (Hordium vulgare L.)-flax-oat (Avena sativa L.)-flax] with standard herbicides. At Carman, this alfalfa rotation provided even better weed control (80% A. fatua, 75% G. spurium) than the conventional rotation. Furthermore, a greater A. fatua control was identified compared to conventional rotation where two consecutive winter cereal crops were grown successfully in rotation (flax-barley-winter triticale (x Triticosecale ex A. Camus)-winter wheat (Triticum aestivum L.)-flax), greater A. fatua control was observed compared to the conventional crop rotation under standard herbicides. Incorporation of silage oat crops did not show consistent management benefits compared to the perennial alfalfa rotation but were generally similar to the conventional rotation with standard herbicides. The results showed that perennial alfalfa in the rotation minimized G. spurium and A. fatua in flax cropping systems, followed by rotations with two consecutive winter cereal crops.

Decomposition of rice straw residues and the emission of CO2, CH4 under paddy rice and crop rotation in the Vietnamese Mekong Delta region – A microcosm study

This study investigated the influence of soil undergoing different crop rotations on the CH₄, CO₂ emissions, and decomposition of rice straw. The studied soil undergoing crop rotation systems were rice-rice-rice (SR) and baby corn-rice-mungbean (SB). Two main microcosm set-ups: anaerobic (SR-AN, SB-AN) and aerobic (SR-AE, SB-AE) conditions. Litter bags containing rice stems were inserted into the soil and recollected at different time points for chemical analysing and the gas sampling was collected to measure the CO₂ and CH₄ emissions. The results indicated that the total carbon (TC) decreased around 30%, and the TC removal in anaerobic was significantly higher than in aerobic conditions. The residue cellulose content varied in a range from 68.2% to 78.6%, while the hemicellulose content varied from 57.4% to 69.3% at day 50 after incorporation. There were no significant differences in the total nitrogen removal, cellulose, hemicellulose, and lignin contents among the microcosm set-ups. CO₂ emission increased in all the microcosm set-ups with the treatments without rice straw (CTSR, CTSB) in both aerobic and anaerobic conditions. CH₄ release in the SR-AN treatments did not differ significantly compared with the SB-AN treatments. This study confirmed that the decomposition of rice straw residues is faster in the anaerobic paddy soil condition compared to the aerobic crop rotation condition.

Adaptation to saline intrusion for agriculture farming transformation in the coastal Ben Tre province, Vietnam

This study aimed to evaluate the adaptive capacity (AC) of agriculture farming transformation to improve for the adaptability by saline intrusion of those culture systems in the coastal Ben Tre province. The primary data was collected by questionnaires in three coastal districts of Ba Tri, Thanh Phu and Binh Dai with 178 households to distribute on agriculture land use transformations. An Object-Based Image Analysis (OBIA) and multi-temporal image analysis approach was developed to detect how LULC changes during 2010-2020 in the coastal Ben Tre province using Landsat TM and OLI data. The MODIS (MOD09 8-day reflectance) data was processed into monthly NDVI maps with the Time Series Product Tool software package and then used to classify regionally common rice crops LULC types using unsupervised classification by ISODATA algorithm. Based on primary data collection, evaluating adaptation measures was assessed the compilation of modification options based on a detailed description and criteria including human, society, infrastructure and natural conditions by standardized a weight ranges of adaptive indicators in the agriculture land use changes. The results detected five agriculture land use transformation including rice-shrimp crop rotation to aquaculture, single rice crop to aquaculture, double rice crop to perennial plant/orchards, double rice crop to rice-shrimp crop rotation, and triple rice crop to double rice crop. The adaptability of these transformations conducted the shrimp-rice crop rotation to aquaculture in Binh Dai of strongly high adaptability. Next is followed by double rice crops to orchards and double rice crops to rice-shrimp crop rotation with high adaptability while the rice-shrimp crop rotation to aquaculture is only moderate in Thanh Phu. The low adaptability levels were identified on single rice crop to aquaculture and triple rice crop to double rice crop transformations due to tolerant condition of saltwater for rice crop cultivation. The studies results can further contribute to support adaptation planning in these sectors by using, developing and streamlining this framework to additional and different socio-ecological contexts.

Oilseed and protein crops grown in French organic farms: an overview of cultivation practices for sunflower and soybean

The development of organic agriculture in France was steady since 2010 but became stronger since 2014. Like other crops, the cultivated areas of organic soybean and sunflower doubled from 2014 to 2018. With a view to better characterize cultural practices in organic production, Terres Inovia and ITAB (in collaboration with Agence Bio) conducted in 2016 and 2017 a national farmers’ survey. These surveys reveal that sunflower was mainly cultivated over the same types of soil than in conventional production but were integrated in more diversified rotations. The main differences between organic and conventional systems concern sowing date and weed control. Organic sunflower was sown very lately compared to conventional one, which impacted the yield severely. Weed were controlled through ploughing, mechanical weeding and crop rotation and weed control was judged as satisfying by a major part of producers. Concerning soybean, a great difference is the use of irrigation which is almost systematic in conventional but concerned only 50% of cultivated area in organic production. Contrary to sunflower, soybean is integrated in short crop rotation, particularly when it was irrigated. This demonstrated the high profitability of soybean in organic systems. Like for sunflower, weed control done through ploughing, mechanical weeding, and crop rotation and weed control was also judged satisfying; nevertheless, criteria on harvest impurities are more severe and to respect them, organic farmers also use hand weeding in complement. These surveys will be reconducted over the years to be able to follow the changes of cultural practices over the years.

A look forward.

This chapter focuses on different management practices in growing cotton, including the use of genetically modified varieties, pesticide application, crop rotation, spacing, irrigation, weed control, integrated pest management and organic farming.