Impacts of different soil fertility improvement practices with film mulched ridge-furrow til-lage on soil nutrient content, maize yield, and water use efficiency in Northwest China.

Improvement of soil quality is one of the most important ways to enhance fertility for efficient dryland crop production. However, the effects of different fertilization measurements with film mulched ridge-furrow tillage on soil fertility, crop yield, and water use efficiency (WUE) of maize largely remain unknown. A three-year field experiment was conducted at the Zhuanglang Experimental Station, Gansu Academy of Agricultural Sciences, located in the semiarid region of the Loess Plateau, Northwest China during 2014-2016. Maize breed Funong No.1 was used during the study. There were four treatments, including: 1) conventional planting (CP, served as control), 2) film mulched ridge-furrow with straw incorporation (FS), 3) film mulched ridge-furrow with optimizing fertilization (FF), and 4) film mulched ridge-furrow with controlled fertilization (FC). Seasonal and yearly changes of soil water content, topsoil organic matter (SOM), soil available nitrogen (AN), phosphorus (AP) and potassium (AK) concentration and crop yield were measured. Nitrogen and phosphorus fertilizer partial factor productivity (PFPN and PFPP), soil profile water storage (WC), crop seasonal water consumption (ET) and water use efficiency (WUE) were calculated. The results showed that FS, FF and FC effectively improved soil fertility via synergistic regulation of soil hydrothermal and nutritional condition. Water-fertilizer interaction effect greatly enhanced incorporated straw decomposition and crop growth, resulting in more returning of straw nutrients and crop biomass to soil, thus significantly increased soil water and fertilizer supply capacity. Compared to CP, the three treatments of FS, FF and FC efficiently increased the concentrations of SOM, AN, AP, and AK by 0.27 g·kg-1, 4.44 mg·kg-1, 0.20 mg·kg-1 and 4.53 mg·kg-1 with an order of FC＞FF＞FS, but had no significant difference among them. Meanwhile, in contrast to pre-sowing WC200, the three year's sum of FS,FF and FC increased WC200 at the end of growing season by 107.41, 38.99 and 28.35 mm, respectively. On average, FS, FC and FF significantly reduced maize ET by 60.50, 37.7 and 34.15 mm to CP, with a relative decrease of 12.6%, 7.9% and 7.1% respectively. By the synergistic effect of modified water and fertilizer environment, the three soil fertility improvement strategies greatly enhanced maize growth from tasseling to maturity stages in the relatively dry year. They affected maize growth in relatively more rain and warmer year, resulting in significantly increased maize yield by improving the yield traits (double ear rate, grain number per ear and 100-grain mass), PFPN, PFPP and WUE. Compared to CP, the PFPN,PFPP of FS, FF and FC increased by 1.82, 1.65, 1.62 and 2.41, 1.69, 1.63 times respectively. Yield and WUE were increased by 5986.1, 4972.31, 4585.63 kg·hm-2 and 13.27, 12.65, 14.01 kg·mm-1·hm-2 correspondingly raised by 81.5%, 67.7%, 62.5% and 86.5%, 82.5%, 91.3%. In conclusion, FS was more effective in water harvesting and drought resistance, while FC and FF were effective for high yield.

[Impacts of climate change on food production in Gansu: A review].

The climate of Gansu turned to be overall warming-drying and partly warming-wetting since 1986. In contrast to that of 1960, the average annual temperature had raised by 1.1°C with the average annual precipitation decreased by 28 mm correspondingly, which made the arid region expanded southward by 50 km in 2010. Climate warming increased the growth period effective accumulated temperature of main food grain crops and lengthened the crop growth period. It changed crop maturity, crop disposition, cropping system and generally increased the cultivatable area and planting altitude above the sea level of major crops and expanded northward the multiple cropping system, which further resulted in expansion of autumn grain crop sown area, shrink of summer grain crop sown area, and replacement of strong winter early maturing varieties by weak winter middle late maturing varieties. It benefited the crop yield by increasing the use efficiency of photo-thermal resources. Warming-wetting climate increased the climate productivity of oasis crop while warming-drying weather decreased the climate productivity of rainfed crops, which were mostly determined by the precipitation regimes and water conditions. Any advanced technique that can increase precipitation use ratio and water use efficiency as well as improve and promote soil quality and fertility should be regarded as an effective countermeasure to increase food grain production under climate change in Gsansu. So, selecting and breeding new crop varieties with the characteristics of strong resistance, weak winter, middle-late mature and high water use efficiency, establishing new planting structure and cropping system that suitable to the precipitation and temperature features of changed climate, are the development direction of food grain production in Gansu to cope with the climate change.

[Effects of plastic film mulching with double ridges and furrow planting on soil moisture and temperature and soybean yield on a semiarid dryland of Gansu Province, Northwest China].

Taking soybean cultivar Jindou 23 as test object, a field experiment was conducted at the Zhenyuan experimental station of Gansu Academy of Agricultural Sciences to study the effects of various plastic mulching treatments on the soil moisture and temperature and soybean grain yield on a semiarid dryland of Northwest China. Four treatments were installed, i. e., plastic film mulching with double ridges and furrow planting (FMRFC), plastic film mulching without ridges and with furrow planting (FMFC), plastic film mulching with strip planting (FMSC), and no mulch strip planting (NMSC, CK). During the drought year (the precipitation in soybean growth period was 246.3 mm) and wet year (407 mm), the daily soil temperature in 0-20 cm layer in all mulching treatments varied in "S" shape, and its fluctuation became smaller with soybean growth. The mulching treatments raised the daily average soil temperature in 0-20 cm layer by an average of 0.5-2.5 degrees C from the seedling (VE-V3) to seed filling (R6) stage, with the average soil temperature in whole growth period raised by 1.3-1.6 degrees C. Both in dry year and in wet year, mulching treatments promoted the soil moisture consumption in 0-120 cm layer, by soybean, but increased the average soil moisture content and water storage in 0-200 cm layer by 1.2%-1.4% and 62.7-70.3 mm, respectively. As compared to CK, treatments FMRFC and FMFC had significant effects in improving the soil temperature and moisture environment in dry year, and greatly improved the yield-related traits such as plant height, branching number, pods per plant, and 100-seed mass. FMRFC increased the yield by 27.7%-51.1% and raised the water use efficiency (WUE) by 47.7%- 56.3%, whereas FMFC increased the yield by 10.2% -25.2% and raised the WUE by 33.3%-35.4%, as compared to CK. It was suggested that FMRFC and FMFC could be the most efficient planting systems for the soybean production in the dryland farming of Northwest China.

(5-Bromo-2-hydroxy-phen-yl)(phen-yl)methanone.

In the title compound, C(13)H(9)BrO(2), the mol-ecular conformation is stabilized by an intra-molecular O-H⋯O hydrogen bond. In the crystal structure, weak inter-molecular C-H⋯O hydrogen-bonding inter-actions link the mol-ecules into chains along the c-axis direction.

2-(4-Phenyl-3H-1,5-benzodiazepin-2-yl)phenol.

In the title compound, C(21)H(16)N(2)O, the dihedral angle between the pendant aromatic rings is 74.2-(1)°.. The conformation is stabilized by an intramolecular O-H⋯N hydrogen bond.