Study on Nutrient Balances of Newly Developed Lowland Rice Fields at Kleseleon Village, Malaka District, Nusa Tenggara Timur

Sukristiyonubowo ,Damasus Riyanto

doi:10.5400/jts.2020.v25i3.137-145

Abstract

The land allocated for newly opened lowland rice can be from ultisols, oxisols, inceptisols, and potential acid sulfate soils. The study was aimed to evaluate nitrogen (N), phosphorous (P), and potassium (K) inputs – outputs of newly developed lowland rice under different treatments and to validate the N, P, and K recommended applications rate according to N, P, and K balances. The study was conducted in Kleseleon village, Malaka District. Five treatments were tested namely T0: farmers practices, T1: NPK at recommendation rate + Rice straw compost, T2: NPK at recommendation rate + Smart + Rice straw compost, T3: ¾ NPK at recommendation rate + Smart + Rice straw compost, and T4: NPK at recommendation rate + Smart + Rice straw compost. The treatments were arranged in a randomized complete block design with three replications. The nutrient balances were constructed according to the difference between nutrient inputs and losses. The results indicated that there were surplus N, P, and K across the treatments and more than adequate to replace N, P, and K removed by harvest products. The suggested N, P, and K application rates were 100 kg urea, 100 kg SP-36, and 100 kg KCl with the addition of compost 3 Mg ha-1 season-1.

Highlights

The land granted for newly opened low land rice fields in Nusa Tenggara Timur Province haveJ Trop Soils, Vol 25, No 3, 2020: 137-145 ISSN 0852-257X ; E-ISSN 2086-6682 many shortcomings (Sukristiyonubowo et al 2014), namely the soils are basic with a low level of macroand micro-nutrients
Sukristiyonubowo et al.: Nutrient Balances of Newly Developed Lowland Rice balance is very complicated, the researchers reported that most assessments are partial analysis of these in-and output data
Nutrient coming from fertilizers (IN1), returned crop residues (IN-2), irrigation (IN-3), rainfall (IN4), as well as biological nitrogen fixation is grouped as nutrient inputs (Sukristiyonubowo et al 2010; Sukristiyonubowo 2007; Wijnhoud et al 2003; Lefroy and Konboon 1999; Smaling et al 1993)

Summary

Introduction

The land granted for newly opened low land rice fields in Nusa Tenggara Timur Province haveJ Trop Soils, Vol 25, No 3, 2020: 137-145 ISSN 0852-257X ; E-ISSN 2086-6682 many shortcomings (Sukristiyonubowo et al 2014), namely the soils are basic with a low level of macroand micro-nutrients. A study on the nutrient balances of newly developed lowland rice in Indonesia neither simple nor complete nutrient balance is still rare and not well documented (Sukristiyonubowo et al 2016). Sukristiyonubowo et al.: Nutrient Balances of Newly Developed Lowland Rice balance is very complicated, the researchers reported that most assessments are partial analysis of these in-and output data Nutrient coming from fertilizers (IN1), returned crop residues (IN-2), irrigation (IN-3), rainfall (IN4), as well as biological nitrogen fixation is grouped as nutrient inputs (Sukristiyonubowo et al 2010; Sukristiyonubowo 2007; Wijnhoud et al 2003; Lefroy and Konboon 1999; Smaling et al 1993). Researchers concluded when the nutrient removals are not replaced by sufficient application of fertilizers or returning of biomass, soil mining takes place and crop production does not reach its potential yields and reduces (Sukristiyonubowo et al 2012; Sukristiyonubowo et al 2010; Sukristiyonubowo 2007; Uexkul 1989)

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