Ammonia Volatilization from Soils Fertilized with Different Nitrogen Type and Application Method in Germination and Early Seedling Stages from the Radish Field

Ammonia volatilization(AV) from basal fertilizer with different nitrogen(N) types and application methods was investigated by the ventilation method in germination and early seedling stages during radish growth seasons in 2014. Four N fertilizer types, urea(U), ammonium bicarbonate(AB), ammonia sulfate(AS), and controlled urea formaldehyde(CUF) were applied through 5 cm depth placement(I) and 10 cm depth placement(II). The results showed that the N fertilizer type was the main factor that caused AV loss in germination and early seedling stages from the radish field. The highest and the lowest cumulative AV losses in germination and early seedling stages from the radish fields were 33.23 and 11.21 N kg/hm^2 for the treatments of AB+I and CUF+II, respectively, accounting for 60.40 and 26.40% of the N application for each treatment. The 10 cm deep placement of N reduced AV rates and lagged the AV process, and CUF significantly reduced ammonia volatilization. The data showed that the suitable N fertilizer type and application method for basal fertilizer were CUF and deep placement, respectively.Therefore, fertilizing with proper N fertilizer types and methods should be the efficient measures to mitigate AV losses from the radish field and will alleviate environment problems.

The Main Evaluation Indicators for the Quality of Fruit Radish

The aim of this study was to establish a scientific evaluation system for fruit radish quality. 8 quality indicators were measured for23 varieties,such as Meinong,Qiaotouqing and Chunbulao. The indicators included root weight,root shape index,water content,crispness,soluble solids,crude fiber,isothiocyanate and vitamin C. These data were analyzed by variation correlation analysis,principal component analysis and system cluster analysis. 23 varieties of fruit radish were analyzed by variation correlation; 8 indicators were compressed into 6 integrated variables using principal component analysis. Finally,the main evaluation indicators of fruit radish were determined by using cluster analysis and correlation analysis. The results indicated that the range of variation coefficient was from 1. 64%-89. 99%. Water content,crispness,soluble solids,crude fiber,isothiocyanate were the important components of fruit radish quality,playing a major role in the quality. These 8indicators were closely related and relatively independent. Water content was significantly and positively correlated with crispness; soluble solids and crude fiber were significantly and negatively related to vitamin C; crispness was significantly and positively correlated with crude fiber and vitamin C. Based on the above results,4 representative indicators were used for evaluating fruit radish quality,that is water content,crispness,soluble solids,crude fiber,which could reflect the most information of fruit radish quality.

Effect of Reducing Application of Chemical Fertilizers and Chemical Pesticides on Physiological Traits,Yield and Quality of Radish

This paper studied the effect of reducing application of chemical fertilizer,increasing application of functional organic fertilizer and trace elements and fully using biological pesticides on physiological traits,yield and quality of radish. The results showed that applying functional organic fertilizer and trace elements and fully using biological pesticides could help to significantly improve the radish fleshy root yield,increase soluble sugar and vitamin C content,reduce crude fiber and nitrate content,but had no significant influence on radish moisture content,glucosinolates and chlorpyrifos content in organophosphorus pesticides.