经济作物替代薯稻三熟制早稻对肥料利用、土壤养分和经济效益的影响

为缩短“薯-稻-稻”三熟制作物早稻的生育期,促进“薯-稻-稻”茬口顺畅衔接,提高整体经济效益,本研究以不同经济作物替代早稻,分别在2016年惠东县和2017年白云区试点进行田间试验,共设置5个处理:休耕T₀(空白对照,不种任何作物)、常规处理T_CK(早稻)、T₁(黄瓜)、T₂(豆角)、T₃(甜玉米),探究不同春播经济作物生育期、产量、种植效益和肥料效率及土壤酶活的差异。结果表明,种植黄瓜、豆角和甜玉米替代早稻均可明显增加经济效益和缩短生育期。其中,T₃效果最优,与T_CK相比,单位面积种植效益增加了1.32~3.72 元·m^-2,生育期缩短了37~43 d,收获指数提高了18.6%~20.1%;同时,增加了土壤有效磷和速效钾含量,增强了土壤脲酶、磷酸酶和过氧化氢酶的活性。综上,甜玉米等经济作物代替早稻形成的“经济作物-中晚稻-冬种马铃薯”三熟轮作模式可以使作物茬口衔接更加顺畅,提升三季作物的整体经济效益,对农民增收具有积极作用。本研究为优化广东乃至华南“薯-稻-稻”三熟区的种植模式提供了理论基础和实践依据。

Effect on Fertilizer Utilization,Soil Nutrients and Economic Benefits of Cash Crops Instead of Early Rice in Potato-Rice Triple Cropping

In order to shorten the growth period of early rice in “potato-rice-rice” triple cropping, make the connection of "potato-rice-rice" more smoothly, and improve overall economic benefits, in this study, different economic crops were used to replace early rice, and field trials were conducted in Huidong County in 2016 and Baiyun District in 2017, respectively. A total of five treatments were set up in the trial: T₀ (blank control, no crops), conventional treatment T_CK(early rice), T₁ (cucumber), T₂ (beans), T₃ (sweet corn), to explored the growth period, yield, planting benefits, fertilizer efficiency and the differences in soil enzyme activity in different spring-sown economic crops. The results showed that planting cucumber, beans and sweet corn instead of early rice could increase the economic benefits and shorten the growth stage significantly. Among them, the sweet corn (T₃) as an economic crop displayed the best results. Compared with spring rice (T_CK), planting sweet corn increased the planting benefit by 1.32~3.72 yuan·m^-2, shortened the growth period by 37~43 days, improved the harvest index 18.6%~20.1%, increased the contents of available phosphorus and available potassium, and increased the activities of urease, phosphatase and catalase in soil. In summary, the model of three-crop rotation of “economic crops-mid-late rice-winter potato” formed by sweet corn and other economic crops instead of early rice made the crop stubble connection more smooth, and improved the overall economic benefits of the triple cropping, which had a positive effect on increasing farmers’ income. This study provides theoretical and practical basis for optimizing the planting pattern of “potato-rice-rice” triple cropping area in Guangdong province and even South China.