Zheng H.-L.,Inner Mongolia Agricultural University |
Liu Y.-C.,Chifeng Academy of Agricultural and Animal Husbandry science |
Qin Y.-L.,Inner Mongolia Agricultural University |
Chen Y.,Inner Mongolia Agricultural University |
Fan M.-S.,Inner Mongolia Agricultural University
Journal of Integrative Agriculture | Year: 2015
The hand-held soil plant analysis development (SPAD) chlorophyll meter has proved to be a promising tool in evaluating the nitrogen status of the potato and guiding fertilization recommendations. In the process of N evaluation of potato plants and N recommendation, it is critical to establish the threshold SPAD value (SPAD reading), below which nitrogen supplement is required. And taking convenient using into account, the threshold needs to be dynamic throughout the potato growing season so that the users can test their potato plants and make fertilization decision at any growing time of potato. To complete this goal, field experiments with different nitrogen supply levels were conducted in different sites in northern China from 2009 to 2011. The results showed that threshold SPAD values decrease as the growing season progresses for all cultivars and planting sites. By statistical analysis, the threshold regression models were established respectively as: y=-0.003x2-0.0507x+58.213 (y, threshold SPAD value; x, days after emergence) for the potato cultivar Kexin 1, and y=-0.003x2+0.017x+52.489 (y, threshold SPAD value; x, days after emergence) for the cultivar Shepody, from which, the threshold SPAD value at any day after emergence can be calculated. © 2015 Chinese Academy of Agricultural Sciences.
Jiang Y.,China Agricultural University |
Zeng Z.H.,China Agricultural University |
Bu Y.,Chifeng Academy of Agricultural and Animal Husbandry science |
Ren C.Z.,Baicheng Academy of Agricultural Science |
And 8 more authors.
Plant, Soil and Environment | Year: 2015
Selenium (Se) is a significant trace element for human and livestock animals because of its physiological functions. Se in plants, especially in the crop plants, is treated as a critical dietary source. The effects of foliar spray together with soil application of Se on Se uptake, distribution in common buckwheat (Fagopyrum esculentum M.) plants were discussed in this study. The results showed that both foliar spray and soil application of Se increased Se uptake in common buckwheat significantly (P < 0.05). The highest Se content was observed in leaves (113.37–690.75 μg/kg), followed by roots (28.98–283.78 μg/kg), grains (26.49–135.89 μg/kg) and stems (23.19–86.80 μg/kg). Se content in grains had the highest correlation coefficient (0.827 and 0.845) with soil Se application treatments. Grain yield of F1 (5 g Se/ha for foliar spray) was 3.65% and 10.25% higher than that of F0 (0 g Se/ha for foliar spray) in two study years, respectively. Under soil Se application conditions, mean grain yields fluctuated from 2890.5–3058.6 kg/ha, 2966.4–3352.8 kg/ha in 2012/2013, respectively. These results indicated a significant interaction effect of foliar spray Se and soil Se application on Se accumulation in common buckwheat. Appropriate Se application might improve common buckwheat grain yield. © 2015 Institute of Agricultural and Food Information. All Rights reserved.