Carbon dioxide enrichment by composting in greenhouses and its effect on vegetable production

Abstract

Concentrations of CO 2 are commonly suboptimal for plant production in greenhouses. Here, a new strategy using crop-residues and animal-manure composting (CRAM) was developed to increase CO 2 concentration throughout the day. During the whole cultivation period, CRAM-treated greenhouses had CO 2 concentrations that were more than twice that of the control greenhouses. This resulted in yields of celery (Apium graveolens L.), leaf lettuce (Lactuca virosa L.), stem lettuce (Lactuca saiva L.), oily sowthistle (Sonchus oleraceus L.), and Chinese cabbage (Brassica chinensis L.) that were 270%, 257%, 87%, 140%, and 227% higher than those in control greenhouses, respectively. The effect of CRAM on vegetable-quality parameters was also examined. Nitrate concentrations deceased in celery, leaf lettuce, oily sowthistle, and Chinese cabbage by 8%, 36%, 30%, and 20%, respectively. The concentrations of soluble sugars in oily sowthistle and Chinese cabbage were significantly increased by the composting procedure. In addition, the ascorbic acid concentrations increased in all five species, with average increases of 13%, 39%, 25%, 72%, and 37% for celery, leaf lettuce, stem lettuce, oily sowthistle, and Chinese cabbage, respectively. It is concluded that CO 2 fertilization using CRAM in greenhouses increases yields and improves quality of common vegetables.

Elevated and super‐elevated CO2 differ in their interactive effects with nitrogen availability on fruit yield and quality of cucumber

“…Super‐elevated CO 2 decreased nitrate and protein accumulation to the same extent with eCO 2 , which indicates that there was no additive improvement of fruit quality resulting from super‐elevated CO 2 as hypothesized. As the nitrate accumulation depends on the relative rates of nitrate assimilation and nitrate uptake, this study demonstrated that both CO 2 treatments inhibited the nitrate uptake to a greater extent than nitrate assimilation in the used soil, which is consistent with previous findings . Both CO 2 treatments, therefore, decrease the potential threats by toxic nitrite and/or N ‐nitroso compounds transformed from nitrate .…”

“…The greater magnitude of carbohydrate accumulation may be attributed to the greater transformation of other compounds to glucose, starch, and dietary fiber. Elevated CO 2 has been shown to increase soluble sugar in vegetables like celery, tomato and lettuce, of starch in potato and palak, and of dietary fiber in carrot, radish, and turnip, which can enhance the taste flavor of fruits and alleviate the health risks caused by certain diseases (e.g. diabetes, cancer, and cardiovascular disease) due to potential greater intake of dietary fiber .…”

“…As the nitrate accumulation depends on the relative rates of nitrate assimilation and nitrate uptake, 6 this study demonstrated that both CO 2 treatments inhibited the nitrate uptake to a greater extent than nitrate assimilation in the used soil, which is consistent with previous findings. 22,44,48 Both CO 2 treatments, therefore, decrease the potential threats by toxic nitrite and/or N-nitroso compounds transformed from nitrate. 49 Furthermore, the greater decrease of nitrate in high N compared with low N by CO 2 treatments has an implication that CO 2 enrichments benefit cucumber quality to a greater extent in the case that the farmer applies excessive N fertilizer; for example, the heavy application rates for vegetable cultivation in China.…”

“…6 Elevated CO 2 decreases the nutritive value of products by decreases in concentrations of protein 19 or mineral 20,21 in spite of increased soluble sugar content and decreased nitrate content. 22,23 The poorer quality can be largely attributed to the dilution effect from greater carbon fixation and carbon accumulation under eCO 2 . 19,24 The imbalance of carbohydrate and other compounds (e.g.…”

Effects of split applications of nitrogen fertilizers on the Cd level and nutritional quality of Chinese cabbage

“…Our results showed that the nutritional quality of Chinese cabbage grown in Cd-added soil was affected by different fertilization methods. Soluble sugar levels are used to evaluate the taste characteristics of vegetables and soluble protein accumulation as an indicator of value for human nutrition (Hurrell, 2003;Jin et al, 2009). The split applications produced a higher level of soluble sugar in the ammonium treatment, and a higher level of soluble protein in the nitrate treatment, compared with the single applica-tions.…”