Effect of Organic and Chemical Fertilizer Application on Growth, Yield, and Soil Biochemical Properties of Landrace <i>Brassica napus</i> L. Leaf-and-Stem Vegetable and Landrace (Norabona)

Abstract

Norabona is generally cultivated in Japan under management systems that use chemical fertilizers and synthetic chemical pesticides. However, the continuous use of these fertilizers and pesticides damages the soil environment and reduces the number of soil microorganisms. There has been little research investigating the effect of organic and chemical fertilizer applications on soil biochemistry and the growth and yield of norabona. In this study, we investigated the effect of organic and chemical fertilizer application on these factors during the norabona growing season from September 2019 to May 2020. Leaf length, shoot height, and shoot width were significantly higher under organic fertilizer management in the early stage of cultivation (in March) than under chemical fertilizer management. However, there was no significant difference between treatments for these growth parameters in later months, nor for any other parameters. Soil TN, and TP contents were significantly higher in the organic fertilizer treatment after harvest than prior to cultivation or after the chemical fertilizer treatment. In addition, soil TC, and volumetric water content were significantly higher in the organic fertilizer treatment than in chemical fertilizer treatment. The higher TC, TN, and C/N ratio in organic fertilizer treated soil appeared to increase the bacterial biomass, leading to enhanced nutrient circulation via N and P circulation activity, producing a rich soil environment with active soil microorganisms.

Effect of Organic and Chemical Fertilizer Application on Apple Nutrient Content and Orchard Soil Condition

“…Where soil microbial activity is low, it is likely that the soil has regularly received chemical fertilizers and pesticides. The average total carbon and bacterial biomass in various kinds of orchard soils are shown in Figure 4 [10,15,32]. In the current study, the organically fertilized soil had greater total carbon and bacterial biomass than the convention chemically fertilized soil.…”

“…Moreover, organic matter in soil acts like a bank by storing the nutrients during the high inputs and releasing during the periods of low input leading to a steady supply of nutrients to the plants [33]. In orchard and other upland agricultural soils, the minimum recommended C and N contents for achieving a high level of nutrient circulation activities are 25,000 and 1500 mg kg −1 , respectively, and the recommended C/N ratio is 10-25 [15,28,29]. In the current study, these recommended values were achieved in the orchard soil under organic fertilization, but not in the soil under chemical fertilizer and pesticide management (Figure 3).…”

“…The tomato field also had higher soil nutrient contents and greater microbial activity and biomass. In another study a vegetable mustard grown under organic fertilization growth parameters such as leaf length, shoot height, and shoot width were higher compared with chemical fertilizer management [15]. Moreover, in a study conducted on different apple orchard cultivation systems, it was found that the highest levels of carbon, nitrogen, phosphorus, and potassium were generally found in the soils of organically farmed orchards, and those orchards also had greater soil microbial activity [10].…”

Tillage and N-source affect soil fertility, enzymatic activity, and crop yield in a maize–rice rotation system in the Indian Terai zone

“…Adverse effects of long-term intensive tillage along with nonjudicious application of chemical fertilizers on depletion of SOC, microbial activity, and nutrient use efficiency have been reported from tropical and sub-tropical environments (Kai and Tamaki, 2020;Bhatt et al, 2019;Chandini et al, 2019). A study in the subtropical region suggested that ZT along with crop residue significantly enhanced the C sequestration rates (Pathak et al, 2017) and improved the microaggregate-associated C content (Bhattacharya et al, 2020), thus resulting in better conservation of SOM and reducing nutrient loss.…”