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The popularized application of annual ryegrass—maize rotation (ARMR) in southern China has been proposed to fully utilize the farmlands and to increase forage yield and quality. Herein, one growth cycle of ARMR was conducted and soil bacteria were analyzed by 16S rRNA sequencing for control (CK), after the preceding crop (monoculture, or mixed sowing of annual ryegrass and oat) and the successive crop (maize). Our results indicated that the α-diversity of soil bacteria was changed in the ARMR system, which was related to the activity of urease and available phosphatase. The mixed sowing of annual ryegrass and oat in preceding crop could improve the yield and quality, while it was accompanied by unbalanced soil community. With the increased sowing proportion of oat to annual ryegrass, the soil pH increased while the soil available phosphatase decreased. The ARMR system was found to benefit the soil microenvironment by increasing the beneficial soil bacteria and enzyme activity or decreasing the harmful soil bacteria. Considering the soil bacteria α-diversity index and physicochemical properties comprehensively, the recommended sowing regime is the mixed sowing of M2 (22.5 kg·hm−2 annual ryegrass with 75 kg·hm−2 oat). [ABSTRACT FROM AUTHOR]

Water shortage is the primary limiting factor for crop production and long-term agricultural sustainability of the North China Plain. Forage cultivation emerged recently in this region. A flyer-year field experiment studies were conducted at Yucheng Integrated Experiment Station to quantify the water requirement and water use efficiency of seven forage varieties under climate variability, that is five annuals, i.e., ryegrass (Secale cereale L.), triticale (×Triticosecale Wittmack), sorghum hybrid sudangrass (Sorghum biolor × Sorghum Sudanense c.v.), ensilage corn (Zea mays L.), prince's feather (Amaranthus paniculatus L.) and two perennials alfalfa (Medicago saliva L.) and cup plant (Silphium perfoliatum L.). Average ET for five annual varieties ranged from 333 to 371 mm, significantly lower than that of the perennial varieties. El of alfalfa is 789 mm, which is higher than that of cup plant. Ryegrass and triticale need 1.5 to 2.0 mm water per day, while others 2.9-4.4 mm. Ensilage corn and Sorghum hybrid sudangrass performed better as their irrigation demand is smaller in the dry seasons than others. Ryegrass needs 281 mm irrigation requirement, which is higher than triticale in dry years. Prince's feather is sensitive to climate change and it can be selected when rainfall is greater than 592.9 mm in the growing season. Mean WUE for prince's feather is 20 Kg ha-1 mm-1, for ensilage corn is 41 Kg ha-1 mm-1 and others is close to 26 Kg ha-1 mm-1. Our experiments indicate that excessive rain will reduce the production of alfalfae. The results of this experiment have implications for researchers and policy makers with water management strategy of forage cultivars and it also very useful in addressing climate change impact and adaptation issues. [ABSTRACT FROM AUTHOR]