Unidirectional compressive properties of magnetorheological (MR) fluids have been investigated under slow compression and constant area with different magnetic fields and different initial gap distances. Experimental tests of unidirectional compression were firstly carried out by using a commercial plate–plate rheometer. The theoretical model based on the continuous squeeze flow theory was developed to calculate the compressive stress. The comparisons between the measured and calculated compressive stresses of MR fluids were made. It showed that the compression resistance of the MR fluid in the magnetic field was much higher than that predicted by the theory. With the increasing magnetic flux density, the deviation between measured and calculated curves accelerated. Characteristics of the compressive stress variation with the reduction in gap distance have been analyzed. The structure strengthening effect induced by the chain structure aggregation in squeeze mode has been used to explain this deviation.

Saline soil reduces soil productivity and exacerbates food security problem. Therefore, it is increasingly necessary to find sustainable farming practices for soil and water conservation. In this regard, conditioning the soil with biochar (BC) or attapulgite (ATP) has been proved as a feasible method of improving water conservation and soil hydraulic characteristics. However, the interactive effect of BC and ATP on saline soil is still unclear. The objective of this study was to investigate the effect of BC and/or ATP on water retention, pore size distribution, hydraulic characteristic parameter, and shrinkage strain of saline soil through laboratory trials. For this purpose, BC and/or ATP were added to the loam soil at three levels of 0%, 2%, and 4% by weight, and saturated in the sodium chloride solution with a concentration of 5 g L À1 . Results showed that the Van Genuchten model accurately fitted the

This experiment was conducted in order to study the effects of commodity functional organic fertilizers on maize yield, soil fertility and economic benefits, and to provide a feasibility basis for the application of functional organic fertilizers instead of chemical fertilizers in maize production. Using seed-producing maize as experimental crop, drip irrigation under the mulch as water supply mode, and different fertilization treatments CK (no fertilization treatment), T1 (3000kg⋅hm−2), T2 (2250kg⋅hm−2), T3 (local method), T4 (Local conventional reduction) in a total of 5 treatments. Research shows that maize yields have different responses under different organic fertilizer conditions. Compared with T3, the plant yield of CK is reduced by 26.4%. The remaining CK, T1, and T3 are increased by 7.8%, 3.4%, and -5.6% respectively compared with T2. Compared with CK, T1, T2, T3 and T4 significantly increased by 31.7%, 28.8%, 26.4%, 22.0%. The difference was significant. The economic shape of fruit spike was also different in response to different modes of functional organic fertilizer application. T1 treatment plants were the highest, reaching 139.8 cm, followed by T3, T4, T2 and CK, which were 11.2%, 4.5%, 8.3%, 6.4% higher than CK compared with T1, T2, T3 and T4, and the difference was significant. T1, T2, T3 and T4 increased by 11.2%, 4.5%, 8.3%, 6.4% compared with the spike length of CK, the difference was significant. ear diameter increased respectively by 20.5%, 21.6%, 20.6%, 14.0%. the difference is significant; compared with CK, the ear rows of T1, T2, T3 and T4 are increased by 5.5% overall. The number of ear rows in the remaining treatments remains between 0.7% and 3.4%. The difference is not significant; the bald tip after each treatment was generally shortened, compared with CK, T1, T2, T3 and T4 are shortened by 44.6%, 28.6%, 12.5%, and 60.4%, respectively. the difference was significant; the number of rows after treatment Compared with CK, T1, T2, T3, and T4 increased by 18.1% overall. The number of ear rows in the remaining treatments remained between 0.3% and 4.7%, with no significant difference. The Spike grain after each treatment increased significantly. Compared with CK, T1, T2, T3, and T4 are increased by 30.1%, 29.5%, 27.6%, and 26.4% respectively. The difference is significant; the 100-seed weight of T1 was the largest, compared with CK, the 100-seed weight of T1, T2, T3 and T4 are increased by 27.7%, 15.6%, 11.1% and 6.1% respectively. the difference was significant. After two years of experiments, the soil fertility of T1 was improved, in which alkaline-hydrolysis nitrogen Basically remain unchanged, the content of rapidly-available potassium and alkaline-hydrolysis nitrogen was slightly increased. The content of available phosphorus was nearly four times higher than before the experiment. The soil is more weakly-alkaline. The comprehensive soil evaluation index is 40% before the test. The comprehensive evaluation was index increased by 54 after the test. The evaluation index was medium. Applying functional organic fertilizer 3000kg⋅hm−2, additional fertilizer is based on the total nutrients of soil nutrients and chemical fertilizers. It can significantly increase the cluster length, panicle diameter, kernel number per row, and grain number per spike of seed-producing maize. while effectively reducing the invalid spike length, providing a guarantee for increasing production at the late stage. The application of functional organic fertilizer is 3000kg⋅hm−2 has a significant increase in yield, which is 7.5% higher than the habitual fertilization of local farmers (average of two-year data).

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