Relationships between wheat yield, yield components and physico-chemical properties of soil under rain-fed conditions

Abstract

<span>This research was conducted to study and classify the physico-chemical<br /><span>properties of soil, yield components of wheat and to determine the significance of<br /><span>these parameters on the grain yield formation. In this research, seven statistical<br /><span>methods consisting of simple correlation analysis (SCA), multiple linear regression<br /><span>(MLR), stepwise regression (SR), factor analysis (FA), principal component<br /><span>analysis (PCA), cluster analysis (CA) and path analysis (PA) have been<br /><span>investigated. The physico-chemical properties of soil, different morphological traits<br /><span>and wheat yield have been obtained from a field with 250×300 meter dimension<br /><span>located in Bajgah (with silty clay loam soil) that consisted of 30 samples. Among<br /><span>statistical analysis performed, MLR has provided more acceptable results. In this<br /><span>method, among the examined characteristics, five traits i.e., the number of stems<br /><span>without spikes per plant, biological yield, harvest index, soil soluble potassium and<br /><span>soil available phosphorus, examined 98.3% of the variations of the yield (P<0.05).<br /><span>Lack of soil nitrogen effect on yield is due to drought stress conditions in which the<br /><span>plant growth is less sensitive to nitrogen. Furthermore, the negative effect of<br /><span>phosphorus on the yield of plant may be due to the inverse relationship between the<br /><span>soil phosphorus and micronutrient elements on the plant growth. Generally, among<br /><span>the yield components, biological yield is the most important and effective trait on<br /><span>grain yield, that has presented a significant contribution in different statistical<br /><span>methods. For some of the used statistical methods, the measured traits, like length<br /><span>of spike, the number of spikes per square meter, the number of grains per spike<br /><span>and harvest index showed positive effects on the grain yield and other traits like</span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span><br /></span><span>1000-grains weight, the weight of grain per spike and the number of tillers without<br /><span>spikes per plant showed negative effects on the grain yield with the highest<br /><span>correlation. Among different soil nutrition, soluble potassium, phosphorus, sulfate<br /><span>and available potassium with positive effects and the clay content with negative<br /><span>effects showed the most correlation with the grain yield.</span></span></span></span><br /><br class="Apple-interchange-newline" /></span>