Fitria, Anita Dwy (2021) VARIABILITAS KESUBURAN TANAH AKIBAT PENGGUNAAN LAHAN DI DAS MIKRO KALIKUNGKUK, BUMIAJI, BATU. Magister thesis, Universitas Brawijaya.
Abstract
Kawasan DAS dibagian hulu umumnya merupakan kawasan yang tersusun oleh penggunaan lahan hutan dan termasuk kedalam wilayah konservasi. Perubahan pola tata guna lahan merupakan hal yang berkembang lama pada kawasan DAS. Kegiatan manusia seperti bercocok tanam dan pemukiman memberikan pengaruh negatif terhadap kualitas DAS sampai kebagian hilir, tak terkecuali bagi kawasan DAS mikro Kalikungkuk yang berada di wilayah Kecamatan Bumiaji, Batu, Jawa Timur. Beragamnya topografi pada kawasan DAS Kalikungkuk berpengaruh terhadap limpasan permukaan, erosi, bahkan longsor. Sehingga mengakibatkan penurunan daya dukung lahan serta penurunan kesuburan tanah yang memicu degradasi lahan. Berdasarkan hasil evaluasi kelas kemampuan lahan di hulu DAS Brantas dimana di dalamnya terdapat DAS mikro Kalikungkuk sebesar 25,67% kawasan DAS mengalami ketidaksesuaian penggunaan lahan. Ketidaksesuaian penggunaan lahan ini dikarenakan perkembangan sektor pertanian dan pariwisata. Menurut Badan Lingkungan Hidup Jawa Timur (2009), luasan hutan pada kawasan hulu DAS Brantas dari tahun 2000-2008 mengalami penurunan 80.938 ha menjadi 42.683 ha. Penelitian ini bertujuan untuk mengevaluasi tingkat kesuburan tanah pada penggunaan lahan hutan, agroforestri, semak belukar dan ladang. Serta mengevaluasi tingkat kesuburan. penggunaan lahan tersebut pada berbagai posisi topografi lereng di DAS mikro Kalikungkuk. Penelitian dilakukan dengan metode survei pada empat penggunaan lahanyaituhutan, agroforestri, semak belukar, dan ladang. Masing-masing penggunaan lahan penelitian berada pada tiga posisi topografi yaitu punggung, lereng dan pelembahan. Setiap plot dilakukan tiga kali ulangan, sehingga secara keseluruhan terdapat 36 plot penelitian. Analisis kesuburan tanah dilakukan dengan analisis kimia N total, P tersedia, K-dd, Ca-dd, Mg-dd, Na-dd, KTK, pH H2O, C organik dan bahan organik tanah. Sedangkan analisis fisika berupa tekstur tanah dan Berat Isi (BI). Pengambilan sampel tanah dilakukan pada kedalaman 0-10, 10-30, 30-50 dan 50-100 cm. Selain itu, untuk menunjang data C organik dan bahan organik tanah dilakukan pengukuran luas bidang dasar(LBD) pohon dan pengambilan sampel seresah pada masing-masing plot penelitian. Hasil data selanjutnya dilakukan Linear mixed effect model (LME) dengan anova pada taraf 5 % dan jika berbeda nyata dilakukan pengujian dengan uji BNT dengan taraf 5%. Hasil penelitian pengaruh topografi terhadap kesuburan tanah dilakukan pada penggunaan lahan hutan dan semak belukar. Hal tersebut dikarenakan pada hutan dan semak belukar tidak terdapat aktivitas pengolahan tanah seperti pemupukan dan pembuatan teras sehingga pengaruh topografi dapat lebih terlihat. Hasil analisis data menunjukkan bahwa tidak ditemukan perbedaan sifat kimia tanah antar topografi di berbagai lapisan tanah (0-10, 10-30, 30-50, dan 50-100 cm) di lahan hutan, kecuali N total (di kedalaman 10-30 cm) dan K-dd (di kedalaman 10-30 dan 30-50 cm). Di sisi lain, sifat fisika tanah seperti bobot isi (BI) berbeda nyata antar topografi di kedalaman 0-10 dan 10-30 cm, dan persentase fraksi pasir, liat dan debu berbeda nyata p<0,05 antar topografi pada semua i kedalaman pengambilan sampel tanah (0-100 cm). Sedangkan di lahan semak belukar, analisis data menunjukkan bahwa topografi tidak berpengaruh terhadap sifat kimia dan fisika diseluruh kedalaman tanah. Oleh karena itu, analisis perbedaan kesuburan tanah antar penggunaan lahan dilakukan pada semua topografi. Hasil analisa data menunjukkan bahwa pengaruh perbedaan penggunaan lahan (hutan, agroforestri, semak belukar, dan ladang) berbeda nyata (p< 0,001) pada hara C organik dan bahan organik tanah pada kedalaman 0-10, 10-30 dan 50-100 cm. Selain itu N total, P tersedia dan K-dd berbeda nyata (p< 0,05) diseluruh kedalaman. Hutan kedalaman tanah 0-10 cm memiliki pH yang lebih tinggi dibandingkan dengan ladang, Ca-dd yang lebih tinggi pula dibanding dengan agroforestri dan semak belukar, serta kandungan Na-dd lebih tinggi 6 kali pada lahan hutan dibandingkan dengan semak belukar dan ladang. Pada penelitian ini kesuburan tanah kedalaman 0-10 cm sangat dipengaruhi oleh penggunaan lahan dimana komposisi tutupan lahan menunjukkan korelasi positif berpengaruh nyata dengan koefisien r tabel diatas 0,3862 pada hara C organik, N total, pH dan KTK. Dalam hal ini secara umum dapat diketahui bahwa ladang memiliki tingkat kesuburan yang lebih rendah dibandingkan dengan hutan. Namun, tidak mungkinnya pengembalian lahan menjadi hutan, maka dibutuhkan alternatif pengelolaan lahan yang tetap menguntungkan bagi petani. Agroforestri memiliki kesuburan yang hampir sama dengan hutan, sehingga dapat menjadi pilihan pengelolaan lahan bagi petani di kawasan DAS mikro Kalikungkuk agar tetap berkelanjutan.
English Abstract
The upstream watershed area is generally an area composed of forest land use and is included in conservation areas. Changes in land use patterns are something that has been developing for a long time in the watershed area. Human activities such as farming and settlements have a negative influence on the quality of the watershed to the downstream part of the river, including the Kalikungkuk micro watershed area, which is in the Bumiaji District, Batu, East Java. The variety of topography in the Kalikungkuk watershed area affects surface runoff, erosion, and even landslides. This results in a decrease in the carrying capacity of the land and a decrease in soil fertility which triggers land degradation. Based on the results of the evaluation of land capability classes in the upstream area of the Brantas watershed, 25.67% of the Kalikungkuk watershed contains a land use mismatch. This land use mismatch is due to the development of the agricultural and tourism sectors. According to Balai Lingkungan Hidup Jawa Timur (2009), the forest area in the upstream area of the Brantas watershed from 2000-2008 decreased by 80,938 ha to 42,683 ha. This study aims to evaluate the level of soil fertility in forest land use, agroforestry, shrubs and fields. As well as evaluating fertility levels. The land use is in various slope topographic positions in the Kalikungkuk micro watershed.The research was conducted using a survey method on four forest land uses, agroforestry, shrubs, and fields. Each of the research land uses was carried out in three topographic positions, namely, slopes and slopes. Each plot was repeated three times, so that there were 36 research plots. Soil fertility analysis was carried out by chemical analysis of total N, available P, K exchange, Ca exchange, Mg exchange, Na exchange, CEC, pH H2O, C organic and soil organic matter. While the physical analysis is in the form of soil texture and weight content (BI). Soil samples were taken at a depth of 0-10, 10-30, 30-50 and 50-100 cm. In addition, to support the C data for organic and organic matter, basal area (LBD) measurements were carried out and litter samples were collected in each research plot. The results of the data are then carried out Linear mixed effect model (LME) with anova at the 5% level and if it is significantly different, the test is carried out with the LSD test with a level of 5%. The results of research on the effect of topography on soil fertility were carried out on forest and shrub land use. This is because in forests and shrubs there are no soil processing activities such as fertilizing and terracing so that the topographic influence can be more visible. The results of data analysis showed that there were no differences in soil chemical properties between topographies in various soil layers (0-10, 10-30, 30-50, and 50-100 cm) in forest land, except for total N (at depths of 10-30 cm. ) and K-dd (at a depth of 10-30 and 30-50 cm). On the other hand, soil physical properties such as bulk density (BI) differ significantly between topographies at depths of 0-10 and 10-30 cm, and the percentage of sand, clay and dust fractions is significantly different between topographies at all soil sampling depths (0-100 cm). Whereas in shurblands, data analysis showed that topography had no effect on chemical and physical properties throughout the soil depth. Therefore, analysis of differences in soil fertility between land uses was carried out in all topographies. The results of data analysis showed that the effect iii of differences in land use (forest, agroforestry, shrubs and crop) was significantly different (p <0.001) on organic C nutrients and soil organic matter at depths of 0- 10, 10-30 and 50-100 cm. In addition, total N, available P, and K exchange were significantly different (p <0.05) at all depths. Forests with a soil depth of 0-10 cm have a higher pH than fields, higher Ca-dd than agroforestry and shrubs, and 6 times higher Na exchange content in forested land compared to shrubs and fields. In this study, soil fertility with a depth of 0-10 cm strongly supports land use where the composition of land cover shows a significant positive effect with r table coefficients above 0.3862 for organic C, total N, pH and CEC. In general, it can be seen that crop have a lower fertility rate than forests. However, it is impossible to return the land to forest, so alternative land management is needed that is still profitable for farmers. Agroforestry has almost the same fertility as forest, so it can be a land management option for farmers in the Kalikungkuk micro watershed area to remain sustainable.
Item Type: | Thesis (Magister) |
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Identification Number: | 0521040001 |
Subjects: | 600 Technology (Applied sciences) > 631 Specific techniques; apparatus, equipment materials > 631.4 Soil science > 631.47 Soil and land-use surveys |
Divisions: | Program Pascasarjana > Magister Pengelolaan Lingkungan, Program Pascasarjana |
Depositing User: | agung |
Date Deposited: | 08 Jul 2022 03:14 |
Last Modified: | 08 Jul 2022 03:14 |
URI: | http://repository.ub.ac.id/id/eprint/191737 |
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