Abstrak. Wilayah lahan kering beriklim kering pada umumnya memiliki curah hujan rendah kurang dari 2000 mm/tahun. Keterbatasan air dan kesuburan tanah yang rendah menjadi kendala dalam pengembangan lahan jenis ini. Selain itu kondisi lahan pada umumnya berbukit dan bergunung dengan solum tanah dangkal dan berbatu. Salah satu upaya peningkatan produktivitas lahan ini adalah melalui aplikasi panca kelola lahan kering iklim kering guna mendukung swasembada pangan, meliputi: pengelolaan air; pemupukan berimbang; pengelolaan bahan organik, ameliorasi dan konservasi tanah; integrasi tanaman ternak; dan penguatan kelembagaan tani. Produktivitas lahan dan indeks pertanaman yang rendah di lahan kering iklim kering memungkinkan untuk ditingkatkan melalui pemberian irigasi suplemen. Sumber irigasi suplemen dapat berasal dari bangunan panen air berupa embung, dam parit, long storage, pemanfaatan air sungai, air tanah dangkal dan dalam. Aplikasi irigasi hemat air bagi tanaman sangat diperlukan pada kondisi air terbatas. Pemupukan berimbang dengan teknologi nano; pengelolaan hara terpadu yang mengkombinasikan pupuk anorganik dengan pupuk organik dan pupuk hayati; pemanfaatan limbah tanaman untuk pakan ternak dan sebaliknya kotoran ternak untuk bahan organik bagi tanaman; serta pendampingan dan pembinaan kelembagaan secara intensif perlu dilakukan untuk keberlanjutan pertanian lahan kering iklim kering. Dryland with dry climate areas generally characterized by low rainfall of less than 2000 mm/year. Water limitations and low soil fertility become obstacles in the development of this type of land. In addition, land conditions are generally have a hilly and mountainous area, shallow solum and rocky soil. One of the efforts to increase land productivity is through the application of five land management of dry land with dry climate area to support food self-sufficiency, such as: water management; balanced fertilization; organic matter management, amelioration and soil conservation; livestock crop integration; and strengthening farmer institutions. Low land productivity and cropping index in dry land with dry climate area makes it possible to increase through the aplication of supplementary irrigation. Sources of supplement irrigation were come from water harvesting infrastructures such as water reservoir, channel reservoir, long storage, river water utilization, shallow and deep ground water. Water saving irrigation are very necessary in limited water conditions. Balanced fertilization with nano technology; integrated nutrient management that combines inorganic fertilizers with organic fertilizers and biological fertilizers; utilization of crop waste for animal feed and vice versa livestock manure for organic material for plants; and intensive institutional assistance and guidance, needs to be carried out for the sustainability of dry land with dry climate agriculture.

Climate change has been affecting agricultural water resources dynamics spatially and temporally. This article presents analysis results of climate change impact on agricultural water availability in Cimanuk Watershed, Indonesia. STREAM was utilized to model agricultural water availability through FAO MOSAICC web application. Climate spatial data time-series were generated using 3 Global Climate Model (GCM), i.e.,: CanESM2, CNRM-CM5, and MPI-ESM-MR following two climate change scenarios of RCP4.5 and 8.5. Model inputs were split into three periods of 1981–2010 (historical), 2010–2039 (near-future), and 2040–2069 (far-future). Historical data model validation showed the efficiency coefficient of the observed and simulated discharge data ratio was 0.68. The results showed a decreasing volumetric water availability from all generated climate data and scenarios, identified by comparing the discharge normal distribution of the historical and future data periods. Whereas, trend analysis of RCP4.5 scenario showed increasing maximum discharge of Cimanuk river using CanESM2 and MPI-ESM-MR GCM’s data, with a Mann–Kendall coefficient of 3.23 and 3.57. These results indicate a different agricultural water balance status within the watershed area, particularly a “very critical” water balance in Indramayu and Majalengka, “critical” in Garut, and “close to critical” in Sumedang Regency.

Analisis Ketersediaan dan Kebutuhan Air Irigasi pada Lahan Sawah : Studi Kasus di Provinsi Sulawesi Selatan

The development of dry land requires precise planning due to its climate-sensitive nature. It is essential to ensure water availability to meet crop water requirements. Rainwater harvesting remains underutilized in upland rice cultivation. The field experiment was conducted in Tulungagung Regency, East Java province, Indonesia from August to December 2017. The research aimed to develop water harvesting technology and irrigation management for upland rice. The nested design was the experimental design with irrigation levels and varieties of upland rice treatments. Four irrigation levels were farmer's customs, 70%, 85%, and 100% of the crop water requirement, while the varieties were Situ Patenggang, Inpago-9, and Inpago-11. Our findings revealed that 70% of the crop water requirement was sufficient for upland rice cultivation in dryland. Crop yields were unaffected by the irrigation level. Differences among upland rice varieties were only significant on plant height character. There was an increased cropping index due to additional water sources in the last months of the dry season until the early rainy season. Rainwater harvesting can be adapted to climate change, especially in areas that often experience water shortages. Keywords: dry land, channel reservoir, irrigation level, crop water requirement

Perubahan iklim telah terjadi secara alamiah di lapisan biosfer sepanjang waktu. Namun, perubahan iklim yang terjadi saat ini makin meningkat intensitas dan lajunya dikarenakan aktivitas manusia melalui emisi antropogenik gas rumah kaca (GRK). Meningkatnya konsentrasi GRK dan suhu permukaan bumi telah menyebabkan pemanasan global yang mengakibatkan terjadinya perubahan iklim yang memberikan dampak yang kompleks pada semua sektor kehidupan manusia. Adaptasi sangatlah penting untuk menjaga keberlanjutan sistem kehidupan di bumi. Adaptasi diartikan sebagai tindakan menyesuaikan diri untuk antisipasi dampak perubahan iklim dengan tujuan meringankan dampak buruk yang dihadapi. Kegiatan adaptasi diharapkan dapat meningkatkan resiliensi terhadap dampak negatif perubahan iklim. Adaptasi dapat berbentuk teknologi, langkah aksi, maupun kebijakan. Selain itu, kearifan lokal menjadi hal yang sangat penting dan memiliki peran sentral dalam upaya adaptasi terhadap perubahan iklim di Indonesia. Buku ini memperkenalkan berbagai teknologi adaptasi dan kearifan lokal pada sektor prioritas RPJMN 2020–2024, yaitu sektor pesisir dan kelautan, ketersediaan sumber daya air, pertanian dan pangan, serta kesehatan. Buku ini diharapkan dapat menjadi sumber literasi guna meningkatkan kesadaran masyarakat terhadap perubahan iklim. Lebih lanjut, teknologi dan kearifan lokal untuk adaptasi perubahan iklim yang ada diharapkan dapat diadopsi oleh masyarakat yang lebih luas.

Spatial and temporal water availability uncertainties are the major constraints to dryland crops productivity. Comprehensive hydrologic survey to determine water harvesting location as supplementary irrigation source is the key to increase dryland cropping index. This research was conducted in Lampung during April to December 2019. The aims of this research were to develop water management designs and irrigation techniques for upland rice and maize cultivation under perennial crops. The applied irrigation techniques consisted of sprinkler, furrow, and hose spray, while 3 varieties of the used upland rice were Rindang 1, Rindang 2, and Inpago 10. Results of this research revealed differences in crop productivity between paddy under “sengon” and rubber. This finding suggests supplement irrigation requirement from water harvesting infrastructures to increase land productivity during dry season. Moreover, the percentage of tolerable shading was up to 50% or 3 year age of the perennial crops.