Study On Cultivation Models For Double-season Maize In Paddy Field In Southern China

To ensure the effects of cultivation pattern on growth and development, yield and yield formation in paddy field in southern China, and select optional pattern to fit the region, double-season maize experiments were conducted in Baitutan Town, Liling City, Hunan Province in 2009. Treatments included nitrogen omission plot (T1), local farmer's practice model(T2), general optimization model (T3), higher fertilizer and density model(T4), and medium fertilizer and density model(T5). We analyzed the main characteristics of yield formation, aboveground dry matter accumulation, nitrogen use efficiency and growth process, The major findings are as follows:(1)There was significantly difference in maize yield between the four models. The yield presented as T4>T5>T3>T2 in both Spring and Fall maize.T4 produced the highest yield of 19.01 t/hm2 in double seasons, which was 42.6% higher over T2 and significantly higher than other patterns. Fall maize produced 41.4% lower yield than Spring maize across four models, and the descend ratio in different models presented as T2(41.8%)>T5(40.8%)>T4(37.8%)> T3(30.3%), which indicated that yield stability in T3,T4 and T5 was higher than in T2.(2) The dry matter accumulation among the four models showed significant difference and presented as T4>T5>T3>T2 in both Spring and Fall maize. T4 produced the highest dry matter of 37.04t/hm2 in double seasons, which was significantly higher than other patterns. T3, T4, and T5 also got higher dry matter production after tasseling than T2. The dry matter distribution focused on the leaves before 12 leaf stage (V12), but decreased gradually in leaves after V12 and increased significantly in stem. The dry matter in ear was increased rapidly after flowering.(3) Nitrogen agronomy use efficiency(AE) were significantly higher in T3,T4 and T5 than in T2 across two seasons although the difference in AE was small among T3,T4 and T5. Stable trend was observed for nitrogen partial factor productivity PFP in different cultivation models, i.e., T3>T5>T4>T2. PFP in T3 averaged 48.9 kg/kg, significantly higher than in any other models across two seasons. Compared to T2, T4 had not significant difference in PFP in Spring maize but significant in fall maize,12% higher than T2.(4) There was significant difference in growth process in different cultivation models. Seedling emergence in T3, T4 and T5 was earlier 2-3 days than in T2. The leaf growth rates in T3,T4 and T5 was 1-1.5 leaf faster compare with in T2. Tasseling in T3, T4 and T5 advanced 3-5 days more than in T2.The grain filling duration in T3, T4 and T5 was significantly longer than in T2. Total growth duration in T4 and T5 was about 5 days shorter than in T2. It suggests that the allocation of annual resources in T4 and T5 was superior to T2.As a whole, treatments T3, T4 and T5 were superior to T2 in yield, dry matter production, growth process, and nitrogen use efficiency(NUE). It suggests that the yield and NUE of double season maize in paddy field in southern China could be significantly enhanced by integrating and optimizing cultivation technology and nutrient management technology.