Potassium Fertilization on Maize under Different Production Practices in the North China Plain

Abstract

All rights reserved. No part of this periodical may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. A gricultural intensification through the use of high-yielding crop cultivars, chemical fertilizers and pesticides, irrigation, and mechanization has been responsible for dramatic increases in grain production in developing countries during the past three decades (Matson et al., 1998). Th ere is, however, a growing global challenge of meeting increased food demand while protecting environmental quality, and this challenge must especially be met in cropping systems that produce maize, rice (Oryza sativa L.), and wheat (Triticum aestivum L.) (Cassman et al., 2002). Th e NCP is one of the most important areas in China for cereal production, accounting for about 48% of the wheat and 39% of the maize produced in the entire country. Th e intensive farming in this region features a continuous wheat-maize cropping system, which requires careful management of soil nutrients. Intensive agriculture has dramatically increased grain production in developing countries, but yield records in the dominant food-producing regions indicate a large gap between the current and potential yields for maize (Neumann et al., 2010), which is an important crop because it contributes to food security in China. Obtaining an increased and sustainable maize yield will probably require integrated measures that could include K fertilization to maintain soil fertility. Potassium is one of the essential nutrient elements for plants; it is involved in the processes of osmoregulation and cell extension, stomatal movement, activation of enzymes, protein synthesis, photosynthesis, phloem loading, and transport and uptake (Marschner, 1995; Pettigrew, 2008). Potassium fertilization is, however, uncommon in the NCP and especially in maize production, primarily due to the relatively high soil test K as surveyed in the 1980s (National Extension Center of Agricultural Technique in China, 2004). In reality, it has oft en been reported that continuous wheat-maize cropping with unbalanced fertilization has rapidly depleted the soil available K (Jin, 1994; Liu et al., 2000; Cao et al., 2007). Many studies have focused on crop response to K fertilization as aff ected by soil properties, application methods, planting systems, etc.

Decomposition of the Factors Determining Changes in China’s Maize Yields

“…5). This result, consistent with recent field experiments (Niu et al 2011, Tan et al 2012, Wu et al 2013, underscores the importance of these nutrients for enhancing production. Increases in phosphorus and potassium levels are attributable to 6.6% and 11.6% increases, respectively, in quantities applied per unit area (Fig.…”

Temporal and spatial variation of soil available potassium in China (1990–2012)

“…The partial K balance (PKB), calculated by taking the ratio of K nutrient removal in aboveground to fertilizer K application rate, was over 1.0 for both cash and grain crops (Fig. 6), showing that K removal by crop uptake was more than K input from K fertilizer application, which was supported by many other studies (Liao et al, 2008;Niu et al, 2011;Tan et al, 2012;Zhang et al, 2011). The PKB was higher with 2.1 (ranging from 1.1 to 4.2) for cash crop than that of 1.3 (ranging from 1.0 to 1.5) for grain crops (Fig.…”

“…Therefore, the increased use of K fertilizer continues to be required on soils planted to grain crops since soil K level for grain crops was below the critical levels and no increase in soil indigenous K supply was observed. These results can be supported by relative yield and a great number of site-to-site reports as well (Yu et al, 2009;Tan et al, 2007Tan et al, , 2010Tan et al, , 2012Zhou, 1999, 2012;Niu et al, 2011). Although with the development of agricultural mechanization and more crop residue being returned back to soils, reports indicated that straw return alone is not sufficient to maintain the soil K balance (Tan et al, 2007(Tan et al, , 2012Wang et al, 2010) and chemical K fertilizer application is essential to maintain both high yield and soil K balance (Xing et al, 2007(Xing et al, , 2010.…”

Effect of Integrated K Management on Productivity and Nutrient Use Efficiency of Maize-Wheat Cropping System

“…K is an important element which plays major role in translocation of different ions in plant part from soil which leads to improvement in various nutrient use efficiencies (Niu et al, 2011). It is concluded that the study showed integrated application of K brought significant improvement in yield of both maize and wheat crops in a cropping cycle compared to sole source of K application.…”