桉树与牧草套种试验研究

Experimental study on the interplanting of Eucalyptus sp and forage grass

为了探讨桉树-牧草复合种植模式的可行性和桉树是否影响牧草的营养成分,试验于2013—2014年在不同郁闭度的桉树林下套种桂牧1号杂交象草、山毛豆、圆叶舞草、非洲狗尾草、合萌、白花扁豆、速生槐等7种牧草,共设计了13种桉-草复合种植模式。结果表明:在不同郁闭度的桉树林下,桂牧1号杂交象草鲜草产量最高的套种模式是新造林(2 m×6 m),达232.35 t/hm2;其次是新造林(2 m×3 m)、萌芽林(2 m×4 m)、萌芽林(2 m×3 m);山毛豆鲜草产量最高的套种模式是新造林(2 m×6 m),达89.0 t/hm2,新造林与萌芽林间产量相比差异显著(P<0.05);在相同郁闭度桉树萌芽林(2 m×3 m)下套种牧草鲜草,再生性最好、生物产量最高的是桂牧1号杂交象草(115.79 t/hm2),其次是非洲狗尾草(94.27 t/hm2),山毛豆(62.53 t/hm2)居第三,圆叶舞草(43.36 t/hm2)居第四。桂牧1号杂交象草、山毛豆等牧草品种在桉树下套种与常规土壤种植的粗蛋白质、粗脂肪、无氮浸出物、钙、磷和氨基酸含量均差异不显著(P>0.05)。说明桂牧1号杂交象草、非洲狗尾草、山毛豆、圆叶舞草4个牧草品种适合在桉树下套种生长,而且桉树对牧草营养价值的影响不明显。

To study the feasibility of Eucalyptus- forage grass compound planting patterns and the effect or not of Eucalyptus sp on the nutritional components of forage grass,further improving the comprehensive economic benefits of Eucalyptus plantation soil,seven forage grasses including（ Pennisetum americanum × P. purpureum） × P. durpureum. cv. Guimu No. 1,Tephrosia candida,Codariocalyx gyroides,Setaria anceps Stapf ex Massey,Aeschynomene indica Linn,Semen dolichoris album,fast growth of Sophora japonica L.,were interplanted under Eucalyptus forest with different canopy density during 2013 to 2014,and the thirteen planting patterns of Eucalyptus- forage grass compound were established in the test. The result showed that under the forest with different canopy density,the interplanting pattern with the highest yield of fresh（ Pennisetum americanum × P. purpureum） × P. durpureum. cv. Guimu No. 1 was the new afforestation（ 2 m × 6 m） with the fresh grass yield of232. 35 t / hm2,followed by the new afforestation,（ 2 m × 3 m）,sprout forest（ 2 m × 4 m）,and sprout forest（ 2 m × 3 m）; the interplanting pattern with the highest yield of fresh Tephrosia candida was the new afforestation（ 2 m × 6 m） with the fresh grass yield of 89. 09 t / hm2,and the fresh grass field of the new afforestation was significant（ P〈0. 05） compared with the sprout forest. Among the interplanted forage grasses under the sprout forest（ 2 m × 3 m） of Eucalyptus sp with the same canopy density,the forage grass with the best regeneration and highest biomass yield was（ Pennisetum americanum × P. purpureum） × P. durpureum. cv. Guimu No. 1 with the yield of 115. 79 t / hm2,followed by Setaria anceps Stapf ex Massey with the yield of 94. 27 t / hm2,Tephrosia candida with the yield of 62. 53 t/hm2,Codariocalyx gyroides with the yield of43. 36 t / hm2. There was no significant differences（ P〉0. 05） in the crude protein,crude fat,nitrogen free extract,the contents of calcium,phosphorus and amino acid of the forage grasses such as（ Pennisetum americanum × P. purpureum） × P. durpureum. cv. Guimu No. 1 and Tephrosia candida between the interplanting under Eucalyptus sp and planting in the conventional soil. The results indicate that the four forage grasses including（ Pennisetum americanum × P. purpureum） × P. durpureum. cv. Guimu No. 1,Setaria anceps Stapf ex Massey,Tephrosia candida,and Codariocalyx gyroides are suitable for the interplanting growth under Eucalyptus sp,and Eucalyptus sp has no obvious effect on the nutritional value of the forage grass.