Comparison Study on Soil Physical and Chemical Properties, Plant Growth, Yield, and Nutrient Uptakes in Bulb Onion from Organic and Conventional Systems

Abstract

<jats:p>This study aimed to compare agricultural practices, soil physical and chemical properties, growth characteristics, and nutrient uptake of bulb onions from organic and conventional farms in southeastern Korea during the 2011–12 growing season. Soil and plant samples were collected from eight certified organic fields managed organically for more than 5 years and eight conventional fields adjacent to the organic fields. The amounts of nutrients applied to onion fields were approximately two times greater with the conventional methods than with organic methods. However, the soil physical and chemical properties were not significantly different between the organic and conventional systems, except for NO<jats:sub>3</jats:sub>-N in early May. Growth characteristics were significantly different in early April with organic bulb yield of 55.9 t·ha<jats:sup>−1</jats:sup>, which was 21.8% lower than conventionally produced onions. Yield reduction in organic onions was the result of lower large-sized (8 cm or greater) bulb yield compared with conventional production. In the conventional system, phosphorus (P) and potassium (K) content of leaf tissue in early April, and nitrogen (N) and P content of bulb tissue in early May were higher than those in the organic system. Uptake of all nutrients was greater in the conventional onions compared with the organic onions, except for leaf tissue at harvest. In conclusion, organic onions began to grow and absorb soil nutrients later than the conventional onions in the initial vegetative growth stage. Moreover, it led to an organic onion producing a lower bulb yield. To accelerate the initial growth of the organic onion plant, agricultural practices need to be modified. Modifications that may help include using larger sized seedlings at transplanting, covering the plants with nonwoven fabric or transparent plastic film to increase warmth during winter, and harvesting the onions 1 week later than the conventional onions.</jats:p>

Soil Fertility, Onion-Maize Productivity and N-Use Efficiency as Affected by Green Manure, Mineral and Bio Fertilizers.

“…Also, high nutrient content in bulbs as a result to activity of roots for longer duration under this treatment. The increase in N, P and K content in bulb were also observed by Sharma et al, (2003), Shaheen et al, (2007), Lee et al, (2015) and Mahala et al, (2018).…”

AMMI model in the analysis of genotype by environment interaction of conventionally and organically grown onion

“…As expected, the highest bulb weight was measured from the plots fertilized with conventional mineral fertilizer, while the bulbs from unfertilized plots performed the poorest (Table 6). Similarly low bulb weights noted for the unfertilized and plots fertilized with farmyard manure might be related to the specifics of the dynamics of nitrogen release from the organic fertilizers (HEINZE et al, 2011;LAMMERTS von BUEREN et al, 2012), which requires the modifications in terms of both agricultural practices and timing of their implementation (LEE, 2010;VIDIGAL et al, 2010;LEE et al, 2014). Bulb weights measured from the organic plots with foliar applied bacterial fertilizer were significantly higher, however still not in the range of the conventional.…”

Long term crop management effects on soil organic carbon, structure, and water retention in a cropland soil in central Ohio, USA

“…Many studies have linked improvements in soil structure not only to increase in water retention, but also to improving gaseous exchanges, root growth, and nutrient availability which would ultimately increase plant productivity ( Haynes and Tregurtha , ; Ferreras et al., ; Gruda , ). Additionally, studies have also shown that the use of mulches (inorganic and organic) also modify the soil microenvironment by regulating soil temperature, reducing water evaporation, suppressing weed growth, and increasing soil microbial activities ( Jackson et al., ; Carrera et al., ; Lee et al., ). One potential draw back from having a larger distribution of macro‐pores (> 50 µm) as a result of rotary ploughing done in the vegetable systems is the potential risk of undesirable solute movement ( i.e ., , herbicide) in the soil, leading to non‐point source pollution and contamination of water resources ( Haynes and Naidu , ).…”