Performance of seedlings of tree borne oilseeds and their response to fertilization in problem soils

Abstract

The aim of the present investigation was to screen the seedlings of tree borne oilseeds (TBOs)suitable for alkali and saline soils and to optimize their fertilizer requirement under different soilenvironments. A nursery experiment was conducted at Forest College and Research Institute,Mettupalayam with four TBOs viz., neem, pungarn, simaruba and jatropha on three soil types viz.,neutral, alkali and saline soils with four fertilizer levels (0:0:0, 100:75: I00, 200: 150:200 and 300:225:300mg N, ~20j and K.zO seedling:'). The soils were .sandy loam in texture with 195, 170 an? 165 kg haI of available N; 1J.6, 10.9 and 9.8 kg ha' of available P; 182,200 and 176 kg ha' of available K and0.48%,0.33% and 0.30 %organic carbon for neutral, alkali and saline soils respectively.

The biometric observations viz., collar diameter, shoot, root and total dry matter production and root:shoot ratio were recorded at 180 days after sowing. The total dry matter production of neem, pungarn,simaruba andjatropha (13.49, 12.19, 11.20 and 17.29 g seedling:', respectively) in alkaii soil was 88.9,96.3, 75.0 and 64.9 per cent respectively as that of neutral soil. Application of 200: 150:200 mg N,P,Oj and Kp scculing' (N,P,K) excelled all other I.~vels for neern (15.37 g seedling:'), pungam(f 4.03 g seedling:') and simaruba (12.84 g seedling ') which has resulted in 40.0, 50.2 and 46.1 percent increase over control. With regard to jatropl:a, the highest total dry matter was recorded with 300:225:300 mg N,P,K seedling:' (19_04· g seedling:") which has registered an increase of39.2 percent over control.

The total dry matter production of neem, pungam, sirnaruba andjatropha (10.89, 13.66,8.76 and 13.07g seed ling", respectively) in sal ine soi I was 7l. 7, J 07.9, 58.6 and 49. J per cent as that of neutral soi I.Neern, pungam and simaruba recorded the highest total dry matter production with 200: 150:200 mgN,P-K seedling:' (14.02,16.79, and 9.74 g seedling.", respectively) recording a percent increase of35. i, 70.1 and 21.9, respectively over control. In the case of jatropha, the highest total dry matter(16.33 g seedling") was recorded with 300:225:300 mg N,P,K seedling:' with an increase of74.7 percent over control.

The present study suggests that pungam and neem were the best suited species for alkali and salinesoils followed by simaruba andjatropha. The performance of the crops was relatively better in alkalisoil than saline soil. The fertilizer requirement under neutral soil was 300:225:300 mg N, PoO- andK,O seedling:' for all the crops. Whereas for alkali and saline soils, the fertilizer requirerrierit forneem, pungam and simaruba was 200: 150:200 mg N,P,K seedling:" and for jatropha, the requirementwas 300:225:300 mg N,P,K seedling':'.