Plant and Soil Science

Amending soil with animal wastes can be useful in food production as well as a means of waste disposal. It has been found to enhance physico-chemical properties and enhance yield. Poultry manure (PM), swine waste (SW), cow dung (CD), and sewage sludge (SS) were added to a hydromorphic ultisol (sandy loam, typic haplusult at the rate of 10 tha-1 (12 kgplot-1)). Maize hybrid (Oba super II) was used as test crop. Randomized Complete Block Design (RCBD) with four replications was used in laying the experiment. Data collected were analyzed using analysis of variance (ANOVA) and means were separated using Fishers' Least Significant Difference (F-LSD). Physical properties of soil influenced by animal wastes include bulk density, total porosity, hydraulic conductivity, gravimetric moisture contents, aggregate stability, and rheological characteristics. Amendments also enhanced soil organic matter, total nitrogen, available phosphorus, potassium, calcium, magnesium and sodium, pH, exchangeable acidity, cation exchange capacity, and base saturation were all higher relative to the unamended plots. Productivity studies revealed that maize growth was significantly affected by amendments especially PM. This was observed in height, leaf area index and yield higher relative to the control. Generally, the increase followed the order PM>SW>SS>CD. Animal wastes especially from poultry sources are recommended for soil amelioration and for increased crop yield in the area.

ABSTRAK Tanah jerlus adalah suatu masalah yang telah lama dihadapi oleh pesawah-pesawah di kawasan Kedah dan Perlis. Tanah jerlus dicirikan oleh nilai kekuatan struktur lapisan tanah keras (hardpan) yang rendah. Sebanyak lima plot telah disediakan untuk ujikaji yang terletak di dalam wilayah Lembaga Kemajuan Pertanian Muda (MADA), Alor Senibong, Langgar, Kedah. Kelima plot ini dibahagikan kepada empat plot yang terdapat masalah tanah jerlus (Plot A, Plot B, Plot C dan Plot D) dan satu plot tanah normal/tidak jerlus (Plot E) sebagai kawalan. Objektif kajian adalah untuk mencirikan nilai kekerasan struktur lapisan keras dan ciri fizik tanah jerlus di kawasan kajian. Nilai kekerasan tanah diukur pada kedalaman 0-100 cm dan sampel profil tanih jerlus diambil daripada setiap titik jerlus bagi penentuan ciri fizik tanih. Hasil kajian menunjukkan bahawanilai kekerasan tanah didapati paling rendah pada kedalaman 0-30 cm iaitu Plot C (0.26 MPa), Plot A (0.28 MPa),Plot B (0.31 MPa)danPlot D (0.34 MPa), manakala Plot E tertinggi dengan nilai 0.84 MPa. Peratus kandungan air tanih adalah lebih tinggi pada Plot C (47.22 %) diikuti oleh Plot A (44.16 %), Plot B (42.60 %), Plot D (41.78 %) dan Plot E (28.88 %). Ketumpatan pukal tanih mengikut susunan menurun adalah Plot E (1.036 gcm-3) > Plot D (1.008 gcm-3) > Plot B (1.006gcm-3) > Plot A (1.003gcm-3) > Plot C (1.002gcm-3). Nilai kekerasan tanah dapat dikaitkan dengan peratus kandungan air dan ketumpatan pukal tanih yang merupakan elemen penting dalam proses pemadatan tanah. Nilai purata kekerasan tanah di kawasan kajian berkorelasi positif dengan ketumpatan pukal tanih (n=15, r=0.78) dan berkorelasi negatif dengan kandungan air tanih (n=15, r=-0.77). Tanah jerlus di kawasan kajian dikelaskan dalam kelas sederhana lembut (0.20-0.40 MPa). Kata kunci: Kekuatan Struktur Lapisan Keras (Hardpan), Ciri Fizik Tanah Jerlus PENGENALAN Tanah jerlus umumnya terjadi disebabkan oleh keadaan tanah yang sentiasa terendam air dan penggunaan tanah secara berterusan tanpa tempoh rehat menjadi faktor utama yang menyebabkan tanah tidak boleh kembali mengeras ke tahap normal. Sehingga tahun 2012, pihak Lembaga Kemajuan Pertanian Muda (MADA) telah pun merekodkan sebanyak 8,107 hektar daripada 96,000 hektar tanah sawah di Kedah dan Perlis terjejas teruk akibat daripada masalah tanah jerlus (New Straits Times 2013). Penjenteraan sawah padi merupakan satu faktor penting dalam pengeluaran padi berhasil tinggi secara komersial. Asas penjenteraan adalah kebolehlalulintasan jentera di atas sawah padi. Oleh itu, kekuatan tanah untuk menampung berat jentera adalah sangat penting. Kekerasan tanah atau lapisan keras tanah (hardpan layer) mestilah sekurang-kurangnya 0.40 MPa supaya dapat menampung berat jentera yang bekerja (Azizul 2008). Tanah lembut atau jerlus yang berpunca dari air bertakung, saliran tidak sempurna dan permukaan tanah yang tidak rata menyebabkan kawasan sawah tidak dapat dikeringkan (Yea dan Ahmad 2008). Oleh itu, beberapa langkah penyelesaian yang telah dilakukan oleh pihak MADA ialah dengan pembinaan parit jari, struktur kecil saliran dan jalan ladang, namun masalah tanah jerlus masih berlarutan sehingga kini. Berdasarkan uraian diatas dapat disimpulkan bahawa kekerasan hardpan tanah merupakan elemen penting yang

A comparison was made between a long-term rice–wheat cultivation with fertilizer nitrogen–phosphorus–potassium (NPK) or added organics [farmyard manure (FYM), paddy straw (PS), green manure (GM)] and a permanent fallow on bulk density (BD), saturated hydraulic conductivity (Ksat), available water capacity (AWC), maximum water-holding capacity (MWHC), aggregation, and soil organic carbon (SOC) dynamics on an Inceptisol of humid subtropics of eastern India. Continuous cropping caused a net decrease in SOC content. Undisturbed fallow was comparable to soils with FYM, PS, and GM amendments in structural and hydrophysical properties. Maximum WHC and AWC values were in the order of FYM followed by PS, GM, fallow, NPK, and control. The relative efficacy of the organics for physical buildup was FYM > PS > GM, which increased structural indices. This study represents further steps toward understanding the ecological importance of fallow management and integrated use of balanced fertilizer and organics.

Background. Faba bean is an important starch-based protein crop produced worldwide. Soil acidity and aluminium toxicity are major abiotic stresses affecting its production, so in regions where soil acidity is a problem, there is a gap between the potential and actual productivity of the crop. Hence, we set out to evaluate acidity and aluminium tolerance in a range of faba bean germplasm using solution culture and pot experiments. Methods. A set of 30 accessions was collected from regions where acidity and aluminium are or are not problems. The accessions were grown in solution culture and a subset of 10 was grown first in peat and later in perlite potting media. In solution culture, morphological parameters including taproot length, root regrowth and root tolerance index were measured, and in the pot experiments the key measurements were taproot length, plant biomass, chlorophyll concentration and stomatal conductance. Result. Responses to acidity and aluminium were apparently independent. Accessions Dosha and NC 58 were tolerant to both stress. Kassa and GLA 1103 were tolerant to acidity showing less than 3% reduction in taproot length. Aurora and Messay were tolerant to aluminium. Babylon was sensitive to both, with up to 40% reduction in taproot length from acidity and no detectable recovery from Al 3+ challenge. Discussion. The apparent independence of the responses to acidity and aluminium is in agreement with the previous research findings, suggesting that crop accessions separately adapt to H + and Al 3+ toxicity as a result of the difference in the nature of soil parent materials where the accession originated. Differences in rankings between experiments were minor and attributable to heterogeneity of seed materials and the specific responses of accessions to the rooting media. Use of perlite as a potting medium offers an ideal combination of throughput, inertness of support medium, access to leaves for detection of their stress responses, and harvest of clean roots for evaluation of their growth.