Maize-soybean relay intercropping is an effective approach to improve the crop yield and nutrient use efficiency, which is widely practiced by farmers in southwest of China.  To elucidate the characteristics of different planting patterns on crop nutrient uptake, soil chemical properties, and soil bacteria community in maize-soybean relay intercropping systems, we conducted a field experiment in 2015–2016 with single factor treatments, including monoculture maize (MM), monoculture soybean (MS), maize-soybean relay intercropping (IMS), and fallow (CK).  The results showed that the N uptake of maize grain increased in IMS compared with MM.  Compared with MS, the yield and uptake of N, P, and K of soybean grain were increased by 25.5, 24.4, 9.6, and 22.4% in IMS, respectively, while the N and K uptakes in soybean straw were decreased in IMS.  The soil total nitrogen, available phosphorus, and soil organic matter contents were significantly higher in IMS than those of the corresponding monocultures and CK.  Moreover, the soil protease, soil urease, and soil nitrate reductase activities in IMS were higher than those of the corresponding monocultures and CK.  The phyla Proteobacteria, Acidobacteria, Chloroflexi, and Actinobacteria dominated in all treatments.  Shannon’s index in IMS was higher than that of the corresponding monocultures and CK.  The phylum Proteobacteria proportion was positively correlated with maize soil organic matter and soybean soil total nitrogen content, respectively.  These results indicated that the belowground interactions increased the crop nutrient (N and P) uptake and soil bacterial community diversity, both of which contributed to improved soil nutrient management for legume-cereal relay intercropping systems.

Using a logistic model, this paper empirically investigated farmers’ perception of climate change and its determinants based on a field survey of 1 350 rural households across five major grain producing provinces in China.  The results show: i) There is an apparent difference in perception levels for long-term temperature and precipitation changes.  Specifically, 57.4% of farmers perceived the long-term temperature change correctly, but only 29.7% of farmers perceived the long-term precipitation change correctly; ii) The factors influencing the farmers’ perceptions are almost completely different between precipitation and temperature, the former are mostly agriculture related, while latter are mostly non-agriculture related, except for farm size; and iii) Farmers are not expected to pay more attention to long-term precipitation changes over the crop growing seasons, because less than 30% of farmers can correctly perceive long-term precipitation change.  Therefore, to improve the accuracy of farmers’ perceptions of climate change, the government is recommended to: i) enhance education and training programs; ii) speed up land transfer and expand household land farm size; iii) develop farmer cooperative organizations; iv) invest more in agricultural infrastructure, specifically in major grain producing regions; and v) improve the agricultural environment and increase farming income.

China is currently the world’s leading producer of Lentinula edodes and owns many cultivated strains of this species.  This study was performed in order to investigate intergenic spacer 1 (IGS1) polymorphism and classification among 49 popular cultivated strains.  The great majority of the 49 strains possessed two different IGS1 sequences, with distinct lengths and homologies.  Based on the length and homology of the IGS1 sequences of the 49 strains, the strains were classified into two groups: A and B.  Group A was subdivided into six subgroups.  Forty-seven strains were homozygous or heterozygous among these six subgroups in group A, Cr01 was heterozygous between A and B, and Guangxiang 9 was homozygous in group B.  An IGS1 polymorphism map of each cultivated L. edodes strain is reported for the first time and could be used as a marker for the initial classification and management of cultivated L. edodes strains in China. 

 

Water availability is a major constraint on grain production in China, therefore, improving irrigation efficiency is particularly important when agriculture faces extreme weather events.  This paper first calculates irrigation efficiency with a translog stochastic frontier production function and then investigates what happens when extreme weather events occur via a Tobit model.  The estimated results reveal several important features of irrigation practices: i) irrigation efficiency is lower when extreme weather events occur; ii) large variations in irrigation efficiency occur across irrigation facilities; iii) the farm plots exhibit an extreme distribution across efficiency levels; and iv) water-saving techniques, technology adoption, and the maintenance of farmers’ economic resilience are major determinants of irrigation efficiency.  Based on these results we propose the following recommendations: i) farmers should balance crop yield and water use; undertake relevant training programs and adopt water-saving techniques; ii) local governments and researchers should help farmers to find the optimal level of irrigation water use based on their own circumstances and provide better water-saving techniques and training programs rather than simply encouraging farmers to invest in irrigation facilities in the most extreme weather years; and iii) the income level of farm households should be increased so as to improve their resilience to natural disasters.