| Since the implementation “Grain for Green” of the Loess Plateau. Jujube as a traditional drought-resistant species, make a significant contribution in local ecological restoration and to bring economic income for residents. Because of its complex terrain conditions( mostly rolling hills),most of the agricultural and forest development are rain-fed. Arid climate and water scarcity, natural rainfall has become the only source of moisture in loess plateau.Drought and water deficiency which are limiting factors in crop growth and yield is a prominent issue. Traditional management in jujube orchard is the clean tillage, which aims to reduce weeds and jujube seedling competition for water and fat in soils. The result of long-term clean tillage in jujube orchard sloping farmland soil moisture evaporation invalid,loose soil and nutrient loss, etc. series of problem, affecting the yield and fruit quality in jujube orchard. In order to change the conditions, it is necessary to seek a more rational soil management which can achieve a healthy development in jujube ecosystem.Foresters(grass)intercropping system has been widely used in Europe, Japan, Africa,Southeast Asia and other global, it is an important measure in the soil management in recent years. In this study, we introduced to cash crops,Feed Brassica napus and Hemerocallis fulva intercropping between rows in jujube orchard, through long-term soil monitoring, analysis of the impact of economic crops on soil moisture in jujube orchard. We have setting 3 treatment:jujube-Hemerocallis fulva intercropping system(JR), jujube-Feed Brassica napus intercropping system(JH) and clean tillage jujube orchard(CK). Wherein the Feed Brassica napus is an annual crop, and the Hemerocallis fulva is a perennial crop. In this experiment we obtained the following results:(1)Feed Brassica napus with Hemerocallis fulvatreatmentimproved the jujube 0-180 cm soil layer, respectively, compared with the control of water treatment increased by 10.1%,6.2% and 13%, 12.1%, the main source of soil moisture each jujube difference two soil in0-20 cm and 20-60 cm; Feed Brassica napus with Hemerocallis fulva rows reduce soil water were compared between the control 9.4%, 29% and 9.9%, 29.8%. Soil moisture reduction occurs mainly in two 60-120 cm and 120-180 cm soil layer.2014 and 2015 at different growth stages of jujube, Feed Brassica napus with Hemerocallis fulva increase the 0-20 cm and20-60 cm soil layer moisture content。(2) During the 2014 seasonal drought, soil moisture intercropping system always be higher than the control treatment. Two kinds of jujube intercropping system has improved soil moisture content, which helps jujube to spend periods of drought. Each soil moisture is mainly consumed in the 0-60 cm soil layer. By the late drought, Hemerocallis fulva soil water consumption reached 80 cm soil layer. In 2015 drought annual rainfall below normal, each soil water consumption is mainly 0-80 cm.(3) 2014 Feed Brassica napus intercropping system jujube and Hemerocallis fulva 0-180 cm soil layer moisture effect is positive; Feed Brassica napus rows between 0-120 cm soil layer moisture effect is positive; Hemerocallis fulva rows between 0-60 cm soil soil moisture effect is positive. 2015 Feed Brassica napus intercropping system jujube 0-180 cm soil layer moisture effects are positive, Hemerocallis fulva jujube intercropping system 60-120 cm soil layer moisture effect is negative, the other soil are positive. Feed Brassica napus rows between 0-60 cm soil layer moisture effect is positive; the rows between Hemerocallis fulva at0-20 cm soil layer moisture effect is positive.In 2014-2015 yearBrassica napus soil moisture competition process occurs only in the0-20 cm soil layer, soil moisture competition Hemerocallis fulva intercropping system have occurred in different soil layers, the highest frequency of 82.7% water competition. 60-120 cm of water to competition the most serious soil. Hemerocallis fulva andBrassica napus intercropping systems SMDR value 2014-2015 year exhibits the opposite trend, Brassica napus rape processing layers SMDR value is substantially positive, Hemerocallis fulva processing within two years SMDR basic value is negative. Description jujube and Hemerocallis fulva competition for water is a common occurrence(4)The results of model simulations jujube, the evaluation parameters of each model are relatively low, only 20 cm soil simulation better. Jujube intercropping system compared by simulating soil moisture and control the process, the gap is not obvious. Since intercropping system to improve antecedent soil moisture content, resulting in intercropping system jujube jujube soil moisture higher than the control. Further research is needed soil moisture simulation accuracy applications HYDRUS-1D model to simulate intercropping system.(5)Based on the above research results, jujube intercropping system could improve the jujube orchardavailable soil moisture. In normal water and in dry years, jujube intercropping system were higher than the soil moisture control treatment. Wherein the best jujube-Brassica napus rapeintercropping system, and rarely competition for water events, thus planting Brassica napus rape among dryland tillage jujube yard rows is a best choice. |
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