Native Arbuscular Mycorrhizal Fungi Characterization from Saline Lands in Arid Oases, Northwest China

Arbuscular mycorrhizal fungi (AMF) colonize land plants in almost every ecosystem, even in extreme conditions, such as saline soils. In the present work, we report the mycorrhizal capacity of rhizosphere soils collected in the dry desert region of the Minqin Oasis, located in the northwest of China (Gansu province), which is characterized by several halophytes. Lycium spp. and Peganum nigellastrum were used as trap plants in a greenhouse experiment to identify autochthonous AMF associated with the halophytes’ rhizospheres. Morphological observations showed the typical AMF structures inside roots. Twenty-six molecularly distinct AMF taxa were recovered from soil and root DNA. The taxonomical diversity mirrors the several AMF adapted to extreme environmental conditions, such as the saline soil of central China. Knowledge of the AMF associated with halophytes may contribute to select specific fungal isolates to set up agriculture strategies for protecting non-halophyte crop plants in saline soils.

Evaluation of energy balances and greenhouse gas emissions from different agricultural production systems in Minqin Oasis, China

Agricultural production in Minqin Oasis, China, is commonly categorized as intensive crop production (ICP), integrated crop–livestock production (ICLP), intensive livestock production (confined feeding) (IFLP), and extensive livestock production (grazing) (EGLP). The objectives of the present study were to use a life cycle assessment technique to evaluate on-farm energy balances and greenhouse gas (GHG) emissions of agricultural production, and to compare the differences among the four systems. Data used in the present study were collected from published literature and face-to face questionnaires from 529 farms in eight towns (two towns per production system) within Minqin county. The ANOVA of averaged data from 2014 to 2015 indicated that the net energy ratio (Output/Input) for the EGLP system was significantly higher than that for any other system (P < 0.01), whereas the difference among other three systems were not significant. The EGLP system generated lower CO2-eq emissions per hectare of farmland than other systems (P < 0.01). Relating carbon economic efficiency to market values (US$) of agricultural products, indicated that the carbon economic efficiency (US$/kg CO2-eq) of the IFLP system was significantly greater than that of other systems (P < 0.01). The major GHG emission sources varied across the systems, that is, soil respiration is the dominant source in EGLP, while the main sources in IFLP are enteric methane and manure management; in ICLP major sources are enteric methane, soil respiration and fertilizer; and in ICP are soil respiration and fertilizer. The structural equation modelling analysis showed that livestock category was strongly linked to net income. The direct effects and total effects of water use efficiency, via its positive influence on energy balances and GHG emissions were much stronger than those of other dependent variables. The study provides important benchmark information to help develop sustainable agricultural production systems on energy balances and GHG emissions in northwestern China.

Evaluation of energy balances and greenhouse gas emissions from different agricultural production systems in Minqin Oasis, China

Agricultural production in Minqin Oasis, China, is commonly categorized as intensive crop production (ICP), integrated crop-livestock production (ICLP), intensive livestock production (confined feeding) (IFLP), and extensive livestock production (grazing) (EGLP). The objectives of the present study were to use a life cycle assessment (LCA) to evaluate the on farm energy balances and greenhouse gas (GHG) emissions of agricultural production, and to compare the differences among the four systems. 529 farmers in eight towns of Minqin Oasis were selected to complete a face-to-face questionnaire. AVONA analysis of the average data from 2014 to 2015 indicated that the net energy ratio (Output/Input) for the EGLP system was significantly higher than for each of the other three systems (P < 0.01), whereas the differences among the other systems were not significant. However, the EGLP system generated lower CO2-eq emissions per hectare of farmland than each of the three other systems (P < 0.01). Relating carbon economic efficiency to market values (Chinese currency, ¥) of agricultural products, indicated that the carbon economic efficiency (¥/kg CO2-eq/farm) of the IFLP system was significantly greater than that of the three other systems (P < 0.01). The net energy ratios of alfalfa (4.01) and maize (2.63) were significantly higher than the corresponding data of the other crops (P < 0.01). All of the emission sources data for ICP, ICLP, IFLP, and EGLP, when related to the contribution of GHG emissions, showed fertilizer, enteric methane emissions, and plastic mulch, contributed the highest proportions of GHG emissions of all production categories. The path models showed that class of livestock was strongly linked to economic income. The direct effects and total effects of water use efficiency, via their positive influence on energy balances and GHG emissions were much stronger than those of other dependent variables. In conclusion, the present study provides benchmark information on the factors for energy balances and GHG emissions for agricultural production systems in northwestern China.

Evaluation of energy balances and greenhouse gas emissions from different agricultural production systems in Minqin Oasis, China

Agricultural production in Minqin Oasis, China, is commonly categorized as intensive crop production (ICP), integrated crop-livestock production (ICLP), intensive livestock production (confined feeding) (IFLP), and extensive livestock production (grazing) (EGLP). The objectives of the present study were to use a life cycle assessment (LCA) to evaluate the on farm energy balances and greenhouse gas (GHG) emissions of agricultural production, and to compare the differences among the four systems. 529 farmers in eight towns of Minqin Oasis were selected to complete a face-to-face questionnaire. AVONA analysis of the average data from 2014 to 2015 indicated that the net energy ratio (Output/Input) for the EGLP system was significantly higher than for each of the other three systems (P < 0.01), whereas the differences among the other systems were not significant. However, the EGLP system generated lower CO2-eq emissions per hectare of farmland than each of the three other systems (P < 0.01). Relating carbon economic efficiency to market values (Chinese currency, ¥) of agricultural products, indicated that the carbon economic efficiency (¥/kg CO2-eq/farm) of the IFLP system was significantly greater than that of the three other systems (P < 0.01). The net energy ratios of alfalfa (4.01) and maize (2.63) were significantly higher than the corresponding data of the other crops (P < 0.01). All of the emission sources data for ICP, ICLP, IFLP, and EGLP, when related to the contribution of GHG emissions, showed fertilizer, enteric methane emissions, and plastic mulch, contributed the highest proportions of GHG emissions of all production categories. The path models showed that class of livestock was strongly linked to economic income. The direct effects and total effects of water use efficiency, via their positive influence on energy balances and GHG emissions were much stronger than those of other dependent variables. In conclusion, the present study provides benchmark information on the factors for energy balances and GHG emissions for agricultural production systems in northwestern China.