The Distribution and Sustainable Utilization of Buckwheat Resources under Climate Change in China

Buckwheat is a promising pseudo cereal and its cultivation history can be traced back to thousands of years ago in China. Nowadays, buckwheat is not only an ordinary crop but also a symbol of healthy life because of its rich nutritional and pharmacological properties. In this research, the current suitable areas of 19 wild buckwheat species were analyzed by the MaxEnt model, which proved that southwestern China was the diversity center of buckwheat. Their morphological characteristics and geographical distribution were analyzed for the first time. In addition, it was found that the change of buckwheat cultivation in three periods might be related to the green revolution of main crops and national policies. Meanwhile, the Sustainable Yield Index (SYI) value of buckwheat in China was the lowest from 1959 to 2016. Through the MaxEnt model, the potentially suitable areas of wild buckwheat would contract while cultivated buckwheat would expand under climate change. Accordingly, the diversity of wild buckwheat will decrease. Therefore, it is necessary to protect buckwheat resources as much as possible to strengthen the development and utilization of buckwheat resources. Moreover, the promotion of buckwheat diversity will be an important trade-off between food security, population growth, and land use under climate change.

The Effect of Crop Rotation and Cultivation History on Predicted Carbon Sequestration in Soils of Two Experimental Fields in the Moscow Region, Russia

Soil organic carbon (SOC) sequestration in arable soils is a challenging goal. We focused on the effect of crop rotation and previous land use for future carbon sequestration on two experimental fields on Retisols with four contrasting fertilization treatments each. We analyzed the SOC dynamics and used the RothC model to forecast the SOC. We found a consistent increase in SOC stocks and stable fractions of the soil organic matter (SOM) with C accumulation in the next 70 years compared to the 90-year experimental period, more evident under the Representative Concentration Pathway 4.5 (RCP4.5) compared with the RCP8.5 scenario. The expected increase in SOC will be higher in the crop rotation with a grass field than in the experiment with an alternation of row crops and cereals. The efficiency depended on stable SOM fractions, and fields with more extended cultivation history showed higher SOM stability. Proper crop rotations are more important for SOC stability than the uncertainty associated with the climate change scenarios that allows timely adaptation. The goal of a 4‰ annual increase of SOC stocks may be reached under rotation with grasses in 2020–40 and 2080–90 when applying a mineral or organic fertilizer system for scenario RCP4.5 and a mineral fertilizer system in 2080–2090 for scenario RCP8.5.

Greenhouse Gas Emissions from Subtropical Agriculture Fields Decrease Over Time

Expansion of cultivated lands and field management impacts greenhouse gas (GHG) emissions from agriculture soils. Soils naturally cycle GHGs and can be sources or sinks depending on physical and chemical properties affected by cultivation and management status. We looked at how cultivation history influences GHG emissions from subtropical soils. We measured CO2, N2O, and CH4 fluxes, and soil properties from newly converted and continuously cultivated lands during the summer rainy season in calcareous soils from south Florida. Newly converted soils had more soil organic matter (OM), more moisture, higher porosity, and lower bulk density, leading to more GHG emissions compared to historically cultivated soils. Although more nutrients make newly converted lands more desirable for cultivation, conversion of new areas for agriculture was shown to release more GHGs than cultivated lands. Our data suggest that GHG emissions from agricultural soils may decrease over time with continued cultivation.

The Effect of Crop Rotation and Cultivation History on Predicted Carbon Sequestration in Soils of Two Experimental Fields in the Moscow Region, Russia

Soil organic carbon (SOC) sequestration in arable soils is a challenging goal for soil management. Multiple factors should be considered for the prediction of the soil capacity to fix atmospheric carbon. In this study, we focused on the effect of crop rotation and previous land use for future carbon sequestration on two experimental fields with identical soils (Retisols) and input of organic fertilizers. We analyzed the SOC dynamics and used the Roth C model to forecast SOC changes under RCP4.5 and RCP8.5 scenarios. Our experimental and modelling results indicated a consistent increase in SOC stocks and the stable fractions of soil organic matter (SOM). The increase in SOC was higher in the experiment with the crop-grassland rotation that in the experiment with a rotation of row crops and barley. With similar total SOC stocks, the efficiency of soil management differed as reflected by the contrasting composition of SOM, as fields with a long cultivation history showed higher SOM stability. The goal of 4‰ annual increase of SOC stocks may be reached under crop- grassland rotation in 2020-40 and 2080-90 when applying mineral or organic fertilizer system for scenario RCP4.5, and mineral fertilizer system in 2080-2090 for scenario RCP8.5.

Application of genome-wide insertion/deletion markers on genetic structure analysis and identity signature of Malus accessions

Background Apple (Malus ssp.), one of the most important temperate fruit crops, has a long cultivation history and is economically important. To identify the genetic relationships among the apple germplasm accessions, whole-genome structural variants identified between M. domestica cultivars ‘Jonathan’ and ‘Golden Delicious’ were used. Results A total of 25,924 insertions and deletions (InDels) were obtained, from which 102 InDel markers were developed. Using the InDel markers, we found that 942 (75.3%) of the 1251 Malus accessions from 35 species exhibited a unique identity signature due to their distinct genotype combinations. The 102 InDel markers could distinguish 16.7–71.4% of the 331 bud sports derived from ‘Fuji’, ‘Red Delicious’, ‘Gala’, ‘Golden Delicious’, and other cultivars. Five distinct genetic patterns were found in 1002 diploid accessions based on 78 bi-allele InDel markers. Genetic structure analysis indicated that M. domestica showed higher genetic diversity than the other species. Malus underwent a relatively high level of wild-to-crop or crop-to-wild gene flow. M. sieversii was closely related to both M. domestica and cultivated Chinese cultivars. Conclusions The identity signatures of Malus accessions can be used to determine distinctness, uniformity, and stability. The results of this study may also provide better insight into the genetic relationships among Malus species.