RESPON PERTUMBUHAN TANAMAN SENGON (PARASERIANTHES FALCATARIA) TERHADAP PEMBERIAN AMELIORAN PADA MEDIA CAMPURAN TANAH PASCATAMBANG BATU KAPUR

Open mining activities have caused soil damage, water pollution, air pollution, and damage to vegetation. Limestone post mining is a critical area that must be rehabilitated to be productive again. This problems can be fixed by doing land reclamation activities which mandated in the Mining Law Number 4, 2009. The success of land reclamation is largely determined by the choice of plant species and the provision of appropriate soil enhancers (ameliorant). This study was aimed to analyze the growth response of sengon plants on giving ameliorant in mixed limestone post mining soil. This study was designed in completely randomized design for 7 treatments and 3 replications used combination of ameliorant: P0 (without ameliorant); P1 (AH 4 kg ha-1); P2 (BFA 350 kg ha-1); P3 (FMA 500 spores plant-1); P4 (the combination of AH and FMA); P5 (the combination of BFA and FMA); and P6 (the combination of AH, BFA, and FMA). Data were processed by analysis of variance at the 0,05 significance level followed by the Least Significant Difference test. The results showed that the best growth response of sengon on giving ameliorant in mixed limestone post mining soil was P1 treatment (humic acid material) which significantly increased root length, root volume, root fresh weight, shoot fresh weight, root dry weight, and shoot dry weight in sengon plants. The addition of ameliorant can be recommended to improve the quality of revegetation plants

Growth Response and Yield of Three Shallot Varieties on The Various Mixed of UREA + ZA in Ultisol Soil

This study aimed to: (1) identify the interaction effect between varieties and mixed doses of urea + ZA on the growth and yield of shallots in Ultisol soil; (2) to identify the effect of each shallot varieties and the dosage mixture of urea + ZA which produce the highest yield in Ultisol soils. The research was conducted from April to June 2019 in Tungkaran Village, Martapura, with a split plot design. The main plot was shallot varieties (V) with three levels, namely Biru Lancor (v1), Bima Brebes (v2), and Super Philip (v3). Subplots were a mixture of urea + ZA (P) with four levels, namely 0 kg urea + 600 kg ZA (p1), 100 kg urea + ZA 400 kg (p2), 200 kg urea + 200 kg ZA (p3), and 300 urea kg + ZA 0 kg (p4). Each experiment was repeated three times. Therefore, there were 36 experimental units. Observation parameters included plant height, number of leaves per clump, number of bulbs per clump, fresh bulbs' weight per clump, and yield of stored dry bulbs. The results showed that the Bima Brebes variety (v2) had a significant effect on plant height, number of leaves, number of bulbs per clump, the weight of fresh bulbs per clump, and yield of stored dry bulbs. The mixture of 200 kg urea + 200 g ZA (p3) significantly affected plant height, number of leaves, number of tubers per clump, the weight of fresh tubers per clump, and yield of stored dry tubers.

Morphological Responses of a Light-Demanding Alstonia scholaris and a Shade-Tolerant Eusideroxylon zwageri to the Air Humidity and Light Intensity

The response of tropical trees to the change of light intensity has been reported to be varied among different species. Some reports argued that the growth was increasing parallel to the increasing of light intensity, but other reports mentioned that the sensitivity to the light intensity was depending on the species. Another environmental factor that has been scientifically proven to affect tree growth is humidity. While humidity itself also directly affected by the light intensity in the forest ecosystems. Therefore, it is possible that the growth pattern of trees under different light intensities is also affected by air humidity under the canopy. This research aimed to study the growth response of a light-demanding Alstonia scholaris and a shade-tolerant Eusideroxylon zwageri to the different levels of air humidity and light intensity. The experiment was conducted in Jambi, Indonesia from April to November 2019. The experiment was carried out using split plot design with factorial treatments. The main plot was the air humidity with three levels and the sub plots was light intensity with five levels. Four replicates were applied. In general, the A. scholaris tends to be more sensitive to the humidity and light intensity compared to E. zwageri. In particular, A. scholaris tends to be more sensitive to the light intensity while, E, zwageri is more sensitive to the humidity. However, there is also strong indication that the effects of light intensity to the growth, especially for A. scholaris, was affected by the humidity level.

Recent changes in the climate-growth response of European larch (Larix decidua Mill.) in the Polish Sudetes

Key message Recently observed temporal changes in the climate-growth relationship of larch in the Polish Sudetes suggest growth limitations in the future. Abstract Larches in the Sudetes are very sensitive to the currently changing climatic factors, and an extreme negative response to drought is observed. In this study, temporal changes in the climate-growth relationship of European larch were analyzed using moving-window correlation. Change-point detection analysis was performed to determine whether there is a temporal connection between tree-ring growth responses and changes in climatic factors trends. The Random Forest predictor importance determination method was used to establish the set of climatic factors that influence larch tree-ring growth the most and to show how this set changes over time. Additionally, cluster analysis was applied to find spatial growth patterns and to generalize the growth response of larch. The results indicate that the main clustering factor is altitude. Nevertheless, an increasing unification of the larch’s response to dominant climatic factors is observable throughout the whole study area. This unification is expressed in the increasingly positive and recently dominant effect of May temperature. A progressively negative influence of the temperature in the summer and late autumn of the year preceding growth was observed, as was an increasing influence of water availability in the summer months. The study indicates that there is a connection between the observed changes and the recent rapid rise in temperature, which has consequently had a negative influence on water availability. The growth of this tree species in the Sudetes is expected to be very limited in the future due to its sensitivity to drought, the predicted increase in temperatures and thermal extremes, and the decrease of the share of summer precipitation in the annual total.